Intelligent footwear systems

ABSTRACT

The invention is directed to intelligent systems for articles of footwear that adjust automatically in response to a measured performance characteristic. The intelligent systems include one or more adjustable elements coupled to a mechanism that actuates the adjustable elements in response to a signal from a sensor to modify the performance characteristic of the article of footwear. The intelligent system adjusts the performance characteristics of the article of footwear without human intervention.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/047,550, filed on Jan. 31, 2005, which is acontinuation-in-part of U.S. patent application Ser. No. 10/385,300,filed on Mar. 10, 2003 the entire disclosures of which are herebyincorporated herein by reference. This application also claims priorityto U.S. Provisional Patent Application Ser. No. 60/557,902, filed onMar. 30, 2004, the disclosure of which is hereby incorporated herein byreference in its entirety.

TECHNICAL FIELD

The invention generally relates to intelligent systems for articles offootwear. In particular, the invention relates to automatic,self-adjusting systems that modify a performance characteristic of thearticle of footwear.

BACKGROUND INFORMATION

Conventional athletic shoes include an upper and a sole. The material ofthe sole is usually chosen with a view towards optimizing a particularperformance characteristic of the shoe, for example, stability orstiffness. Typically, the sole includes a midsole and an outsole, eitherof which can include a resilient material to protect a wearer's foot andleg. One drawback with conventional shoes is that performancecharacteristics, such as cushioning and stiffness, are not adjustable.The wearer must, therefore, select a specific shoe for a specificactivity. For example, for activities requiring greater cushioning, suchas running, the wearer must select one type of shoe and for activitiesrequiring greater stiffness for support during lateral movement, such asbasketball, the wearer must select a different type of shoe.

Some shoes have been designed to allow for adjustment in the degree ofcushioning or stiffness provided by the sole. Many of these shoes employa fluid bladder that can be inflated or deflated as desired. Adisadvantage presented by these shoes is that one or more of thebladders can fail, rendering the cushioning system effectively useless.Moreover, many of the shoes employing fluid bladders do not allow forsmall-scale changes to the degree of cushioning provided by the sole.Often, the change to the degree of cushioning provided by the sole inpressurizing or depressurizing, or in partially pressurizing orpartially depressurizing, a bladder will be larger than that desired bythe wearer. In other words, bladders are typically not capable of fineadjustments.

A further disadvantage of many of the shoes designed to allow foradjustment in the degree of cushioning or stiffness provided by the soleis that they are only manually adjustable. Accordingly, in order toadjust such shoes the wearer is required to interrupt the specificactivity in which he/she is engaged. With some shoes, the wearer mayalso be required to partially disassemble the shoe, re-assemble theshoe, and even exchange shoe parts. Moreover, the wearer, to his or herdissatisfaction, may be limited in the amount of adjustment that can bemade.

Some shoes have been designed to automatically adjust the degree ofcushioning or stiffness provided by the sole. These shoes measure theamount of force or pressure exerted on the sole by the wearer's footwhen the wearer's foot strikes the ground. Through analysis andinvestigation, it has been discovered that the mere measurement of forceor pressure alone, however, is too limited, as it provides noinformation relating to the performance of the shoe. For example,measuring force provides no indication as to whether the sole has eitherover-compressed or under-compressed for that particular wearer withoutprior investigation into the normal forces exerted by the wearer duringthe activity. If the sole is either over-compressed or under-compressed,the shoe is poorly matched to the wearer's activity and needs. Inessence, the wearer's body has to adapt to the shoe. The biomechanicalneeds of the wearer are poorly met, if at all.

In sum, shoes that have been designed to allow for some adjustment inthe degree of cushioning or stiffness provided by the sole still fallshort of accommodating the wearer's needs. Specifically, they are notfully adjustable throughout the range of the biomechanical needs of theparticular wearer or lack the ability to sense the true needs of thewearer. As a result, the wearer must still, in some way, adapt his orher body to the environment presented by the shoe.

There is, therefore, a need for a shoe that senses the biomechanicalneeds of the wearer, automatically adjusts a performance characteristicof the shoe to accommodate the biomechanical needs of the wearer, forexample the degree of cushioning or stiffness provided by the sole, andavoids the drawbacks of bladder cushioning or manually adjustable shoes.

SUMMARY OF THE INVENTION

The invention is directed to intelligent systems for articles offootwear that adjust a feature of the footwear in response to thefootwear's environment, without human interaction. In other words, thefootwear is adaptive. For example, the intelligent system cancontinuously sense the biomechanical needs of the wearer andconcomitantly modify the footwear to an optimal configuration. Theintelligent system includes a sensing system, a control system, and anactuation system. Further, the intelligent system can sense theconditions of use of the article of footwear, understand under whatcondition the article of footwear is being used, and adapt the articleof footwear accordingly.

The sensing system measures a performance characteristic of the articleof footwear and sends a signal to the control system. The signal isrepresentative of the measured performance characteristic. The controlsystem processes the signal to determine if, for example, theperformance characteristic deviates from an acceptable range or exceedsa predetermined threshold. The control system sends a signal to theactuation system relative to the deviation. The actuation systemmodifies a feature of the footwear in order to obtain an optimalperformance characteristic.

In one aspect, the invention relates to an intelligent system for anarticle of footwear. The system includes a control system, a powersource electrically coupled to the control system, an adjustableelement, and a driver coupled to the adjustable element. The driveradjusts the adjustable element in response to a signal from the controlsystem.

In another aspect, the invention relates to an article of footwearincluding an upper coupled to a sole and an intelligent system at leastpartially disposed in the sole. The system includes a control system, apower source electrically coupled to the control system, an adjustableelement, and a driver coupled to the adjustable element. The driveradjusts the adjustable element in response to a signal from the controlsystem.

In various embodiments of the foregoing aspects, the system modifies aperformance characteristic of the article of footwear, such ascompressibility, resiliency, compliancy, elasticity, damping, energystorage, cushioning, stability, comfort, velocity, acceleration, jerk,stiffness, or combinations thereof. In one embodiment, the adjustableelement is adjusted by at least one of translation, rotation,reorientation, modification of a range of motion, or combinationsthereof. The system may include a limiter for limiting a range of motionof the adjustable element. The control system includes a sensor andelectrical circuitry. The sensor may be a pressure sensor, a forcetransducer, a hall effect sensor, a strain gauge, a piezoelectricelement, a load cell, a proximity sensor, an optical sensor, anaccelerometer, a hall element or sensor, a capacitance sensor, aninductance sensor, an ultrasonic transducer and receiver, a radiofrequency emitter and receiver, a magneto-resistive element, or a giantmagneto-resistive element. In various embodiments, the driver may be aworm drive, a lead screw, a rotary actuator, a linear actuator, a geartrain, a linkage, a cable driving system, a latching mechanism, a piezomaterial based system, a shape memory material based system, a systemusing a magnetorheological fluid, a system using an inflatablebladder(s), or combinations thereof.

In still other embodiments, the adjustable element may be at leastpartially disposed in at least one of a forefoot portion, a midfootportion, and a rearfoot portion of the article of footwear. In oneembodiment, the article of footwear has a sole including an outsole anda midsole and the adjustable element is disposed at least partially inthe midsole. In various embodiments, the adjustable element may begenerally longitudinally disposed within the article of footwear, or theadjustable element may be generally laterally disposed within thearticle of footwear, or both. For example, the adjustable element mayextend from a heel region to an arch region of the article of footwearor from an arch region to a forefoot region of the article of footwearor from a forefoot region to a heel region of the article of footwear.Furthermore, the adjustable element may be at least partially disposedin a lateral side, or a medial side, or both of the article of footwear.

In another aspect, the invention relates to a method of modifying aperformance characteristic of an article of footwear during use. Themethod includes the steps of monitoring the performance characteristicof the article of footwear, generating a corrective driver signal, andadjusting an adjustable element based on the driver signal to modify theperformance characteristic of the article of footwear. In oneembodiment, the steps are repeated until a threshold value of theperformance characteristic is obtained.

In various embodiments of the foregoing aspect, the generating stepincludes the substeps of comparing the monitored performancecharacteristic to a desired performance characteristic to generate adeviation and outputting a corrective driver signal magnitude based onthe deviation. In one embodiment, the corrective driver signal has apredetermined magnitude. Further, the monitoring step may include thesubsteps of measuring a magnetic field of a magnet with a proximitysensor, wherein at least one of the magnet and the sensor are at leastpartially disposed within the sole and are vertically spaced apart in anunloaded state, and comparing the magnetic field measurement duringcompression to a threshold value. In one embodiment, the monitoring stepinvolves taking multiple measurements of the magnetic field duringcompression and comparing an average magnetic field measurement to thethreshold value.

In additional embodiments, the method may include the step of limiting arange of motion of the adjustable element with a limiter and theadjusting step may include adjusting the limiter a predetermineddistance. The adjustment step may be performed when the article offootwear is in an unloaded state. In one embodiment, the adjustment stepis terminated when a threshold value of the performance characteristicis reached.

In various embodiments of all of the foregoing aspects of the invention,the adjustable element may be an expansion element, a multiple densityfoam, a skeletal element, a multidensity plate, or combinations thereof.The adjustable element may exhibit an anisotropic property. In oneembodiment, the adjustable element may be a generallyelliptically-shaped expansion element. Further, the system may include amanual adjustment for altering or biasing the performance characteristicof the adjustable element, or an indicator, or both. The manualadjustment may also alter a threshold value of the performancecharacteristic. The indicator may be audible, visual, or both. Forexample, the indicator may be a series of electro-luminescent elements.

In another aspect, the invention relates to a system for measuringcompression within an article of footwear. The system includes a sensorat least partially disposed within a sole of the article of footwear anda magnet generally aligned with and spaced from the sensor. The sensormay be a hall effect sensor, a proximity sensor, a hall element orsensor, a capacitance sensor, an inductance sensor, an ultrasonictransducer and receiver, a radio frequency emitter and receiver, amagneto-resistive element, or a giant magneto-resistive element. Thesystem may include a processor. In one embodiment, the sensor measures amagnetic field generated by the magnet and the processor converts themagnetic field measurement into a distance measurement representing anamount of compression of the sole in correlation with respective timemeasurements. The processor may convert the distance measurements into ajerk value, a value representing acceleration, a value representingoptimal compression, and/or a value representing a compression force.

In various embodiments of the foregoing aspect, the system furtherincludes a driver coupled to the sensor and an adjustable elementcoupled to the driver. The system may include a limiter for limiting arange of motion of the adjustable element. In one embodiment, aperformance characteristic of the article of footwear is modified inresponse to a signal from the sensor. In one embodiment, the signalcorresponds to an amount of compression of the sole.

In another aspect, the invention relates to a method of providingcomfort in an article of footwear. The method includes the steps ofproviding an adjustable article of footwear and determining a jerkvalue, a value representing acceleration, a value representing optimalcompression, and/or a value representing a compression force. The methodmay further include the step of modifying a performance characteristicof the adjustable article of footwear based on the jerk value, the valuerepresenting acceleration, the value representing optimal compression,or the value representing a compression force.

In another aspect, the invention relates to a method for modifying aperformance characteristic of an article of footwear during use. Themethod includes the steps of measuring a sensor signal from a sensor atleast partially disposed within a sole of the article of footwear, anddetermining whether the sole has compressed. The method also includes,upon determining that the sole has compressed, the step of determiningwhether adjustment of the sole is required, and, upon determining thatadjustment of the sole is required, the step of adjusting the sole.

In various embodiments of the foregoing aspect, the method furtherincludes the steps of receiving a user input related to adjustment ofthe sole from a user of the article of footwear, adjusting a hardnesssetting for the sole in response to receiving the user input, anddisplaying the hardness setting for the sole by activating at least oneelectro-luminescent element, such as a light-emitting diode (LED) or anorganic light emitting diode (OLED), disposed on the article offootwear. The method may also include the step of calculating at leastone threshold of compression in response to receiving the user input.The at least one threshold of compression, which may be a lowerthreshold of compression and/or an upper threshold of compression, maybe for use in determining whether adjustment of the sole is required.

In one embodiment, the step of measuring the sensor signal includessampling the sensor signal a plurality of times. The step of measuringthe sensor signal may also include calculating an average value for thesensor signal by averaging a subset of the plurality of samples of thesensor signal.

In another embodiment, the step of measuring the sensor signal isrepeated at least once to obtain a plurality of measurements of thesensor signal. In one such embodiment, the step of determining whetherthe sole has compressed includes calculating a difference between anaverage of a plurality of previously obtained measurements of the sensorsignal and the most recently obtained measurement of the sensor signal.The step of determining whether the sole has compressed may also includecalculating this difference each time a new measurement of the sensorsignal is obtained and/or determining whether a predetermined number ofthose calculated differences is greater than a predetermined constant.

In yet another embodiment, the step of measuring the sensor signalincludes measuring compression in the sole. In one such embodiment, thestep of determining whether adjustment of the sole is required includesdetermining the maximum amount of measured compression in the sole.

In still another embodiment, the step of determining whether adjustmentof the sole is required includes determining whether there is a changein a surface condition on which the article of footwear is used. In oneembodiment, the step of determining whether there is a change in thesurface condition on which the article of footwear is used includesdetermining whether there is a change in a first parameter over time andsubstantially no change in a second parameter over time. In otherembodiments, the step of determining whether there is a change in thesurface condition on which the article of footwear is used includesdetermining whether there is a change in an absolute compression in thesole over time and substantially no change in a deviation of thecompression in the sole over time, or alternatively, determining whetherthere is a change in the deviation of the compression in the sole overtime and substantially no change in the absolute compression in the soleover time.

The surface condition on which the article of footwear is used may bedetermined to have changed from a hard ground surface to a soft groundsurface. Alternatively, the surface condition may be determined to havechanged from a soft ground surface to a hard ground surface. In oneembodiment, the determination of whether there is a change in thesurface condition on which the article of footwear is used is made aftera wearer of the article of footwear has taken a plurality of steps.

In a further embodiment, the step of determining whether adjustment ofthe sole is required includes determining that the compression in thesole is less than a lower threshold of compression. In such a case, thestep of adjusting the sole includes softening the sole. Alternatively,in another embodiment, the step of determining whether adjustment of thesole is required includes determining that the compression in the soleis greater than an upper threshold of compression. In this latter case,the step of adjusting the sole includes hardening the sole. In oneembodiment, the adjustment of the sole is made after a wearer of thearticle of footwear has taken a plurality of steps.

Additionally, the step of adjusting the sole may include actuating amotor located within the sole. In one such embodiment, the methodfurther includes the step of determining the status of the motor locatedwithin the sole. Determining the status of the motor may includesampling a battery voltage or using a potentiometer, an encoder, or anyother suitable type of measuring device.

In another aspect, the invention relates to a controller for modifying aperformance characteristic of an article of footwear during use. Thecontroller includes a receiver configured to receive a first signalrepresenting an output from a sensor at least partially disposed withina sole of the article of footwear, a determination module configured todetermine whether the sole has compressed and to determine whetheradjustment of the sole is required, and a transmitter configured totransmit a second signal for adjusting the sole.

In another aspect, the invention relates to an article of footwear thatincludes an upper coupled to a sole and a controller at least partiallydisposed within the sole. The controller includes means for receiving afirst signal representing an output from a sensor at least partiallydisposed within the sole, means for determining whether the sole hascompressed and for determining whether adjustment of the sole isrequired, and means for transmitting a second signal for adjusting thesole.

In another aspect, the invention relates to a method for modifying aperformance characteristic of an article of footwear during use. Themethod includes the steps of measuring a sensor signal from a sensor atleast partially disposed within a sole of the article of footwear,determining whether the article of footwear has experienced a peakcondition, if so, determining whether adjustment of the article offootwear is required, and, if so, adjusting a performance characteristicof the article of footwear.

In various embodiments of the method, the peak condition is based on achange in state of the article of footwear as a result of an activityresulting in a compression criterion, such as a jump, a landing, asprint, a turn, a cut, a push-off, and a stop. In some embodiments, theactivity may cause an irregular profile. The change in state of thearticle can be represented by at least one of absolute compression, rateof compression, frequency of compression, change in rate of compression,uneven compression, velocity, acceleration, jerk, and combinationsthereof. For example, if a wearer of an article of footwear embodyingthe invention experiences excessive pronation, the system senses unevencompression across the sole and can stiffen the sole, or portionsthereof, as necessary to compensate therefor. Additionally, changes inthe rate of compression may indicate that the wearer is changing pacefrom walking to sprinting, thereby warranting changing a performancecharacteristic of the shoe to compensate therefor. The method canfurther include the step of adjusting a threshold value for determiningthe peak condition. The method can include the step of evaluating whenthe peak condition is over and returning the threshold value to itsprevious setting. Various embodiments of the method can also includetracking a plurality of peak conditions experienced by the article offootwear and determining a new threshold value for determining whetherthe article of footwear has experienced a peak condition based on theplurality of peak conditions experienced. For example, the thresholdsetting for a particular user may be too low for the particular activityengaged, which can be determined by the system analyzing the pluralityof peak conditions. The system can then adjust the threshold value orperformance characteristic as necessary.

The method can further include the steps of monitoring a state of thearticle of footwear, determining if the article is inactive and, if so,enabling a sleep mode in the intelligent system. The step of monitoringthe state of the article of footwear can include sampling the sensorsignal at set intervals and, in one embodiment, determining whether thesensor signal has remained substantially constant for a set time period.The step of enabling a sleep mode in the intelligent system can includereducing power to at least one portion of the intelligent system. Theintelligent system can be reactivated upon an indication of use of thearticle of footwear, such as a vibration, a force, acceleration,velocity, and an increase in temperature within the shoe or a change inelectric or other field strength within the shoe (such as a change incapacitance). In addition, the method can include the steps of receivinga user input related to an adjustment of the performance characteristicthrough a user interface and adjusting an adjustable element at leastpartially disposed within the article of footwear in response to theuser input. In one embodiment, the user interface can be a capacitiveuser interface, a button, a switch, a slider, a dial, or combinationsthereof. The method can include providing an indication of a setting ofthe performance characteristic through an indicator, for example atleast one electro-luminescent element disposed on the article offootwear.

In another aspect, the invention relates to an intelligent system foradjusting a performance characteristic of an article of footwear. Thesystem includes a control system, a power source electrically coupled tothe control system, an adjustable element, a driver coupled to theadjustable element for adjusting the adjustable element in response to asignal from the control system, and at least one user interface. Theuser interface can be a capacitive user interface, a button, a switch, aslider, a dial, or combinations thereof. A setting of the performancecharacteristic can be adjusted based on an input through the userinterface.

In various embodiments, the driver includes a motor shaft and a sensorfor determining an angular position or rotation counts of the motorshaft or number of shaft rotations. The sensor can be a magnetic sensor,any field sensor, a mechanical sensor, an optical sensor, orcombinations thereof. The control system, power source, adjustableelement, and driver can be arranged in a substantially horizontalorientation within a sole of the article of footwear. Such anarrangement can be used to reduce the overall height of the sole of thearticle of footwear.

In one embodiment, at least one of the control system, power source,adjustable element, and driver can be housed in a waterproof casing. Inthis embodiment, the waterproof casing can enable the intelligent systemto perform when subjected to high levels of moisture. An assembly of thecontrol system, the power source, the adjustable element, and the drivercan also include a plurality of gaskets to render the assemblywaterproof.

These and other objects, along with advantages and features of thepresent invention herein disclosed, will become apparent throughreference to the following description, the accompanying drawings, andthe claims. Furthermore, it is to be understood that the features of thevarious embodiments described herein are not mutually exclusive and canexist in various combinations and permutations.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention. In the followingdescription, various embodiments of the present invention are describedwith reference to the following drawings, in which:

FIG. 1 is a partially exploded schematic perspective view of an articleof footwear including an intelligent system in accordance with oneembodiment of the invention;

FIG. 2A is an exploded schematic perspective view of a sole of thearticle of footwear of FIG. 1 in accordance with one embodiment of theinvention;

FIG. 2B is an enlarged schematic side view of the intelligent system ofFIG. 2A illustrating the operation of the adjustable element;

FIG. 3 is a schematic perspective view of an alternative embodiment ofan adjustable element in accordance with the invention;

FIGS. 4A-4E are schematic side views of alternative embodiments of anadjustable element in accordance with the invention;

FIG. 5A is a schematic side view of the article of footwear of FIG. 1showing select internal components;

FIG. 5B is an enlarged schematic view of a portion of the article offootwear of FIG. 5A;

FIG. 6 is a schematic top view of a portion of the sole of FIG. 2A witha portion of the sole removed to illustrate the layout of selectinternal components of the intelligent system;

FIG. 7 is an exploded schematic perspective view of a sole of thearticle of footwear of FIG. 1 in accordance with another embodiment ofthe invention;

FIGS. 8A-8G are schematic perspective views of various components thatmay be included in various embodiments of the sole of FIG. 7 inaccordance with the invention;

FIG. 9 is a schematic bottom view of the midsole of FIGS. 7 and 8G inaccordance with one embodiment of the invention;

FIG. 10 is a schematic bottom view of an optional torsional bar that maybe used with the sole of FIG. 7 in accordance with one embodiment of theinvention;

FIG. 11 is a schematic bottom view of the optional torsional bar of FIG.10 disposed on the midsole of FIG. 9 in accordance with one embodimentof the invention;

FIG. 12 is a schematic bottom view of the midsole and the optionaltorsional bar of FIG. 11, further including additional heel foamelements in accordance with one embodiment of the invention;

FIG. 13 is a schematic bottom view of the midsole and the optionaltorsional bar of FIG. 11, further including additional components inaccordance with one embodiment of the invention;

FIG. 14 is a schematic bottom view of the midsole of FIG. 13 furtherincluding the additional heel foam elements of FIG. 12 in accordancewith one embodiment of the invention;

FIG. 15 is a schematic bottom view of the midsole of FIG. 14 furtherincluding a casing that covers the various components of the intelligentsystem in accordance with one embodiment of the invention;

FIG. 16 is a schematic lateral perspective view of a sole including ahoneycombed shaped expansion element and a user interface in accordancewith one embodiment of the invention;

FIG. 17 is a schematic lateral side view of the sole of FIG. 16;

FIG. 18 is an enlarged schematic lateral perspective view of the userinterface of FIG. 16 in accordance with one embodiment of the invention;

FIG. 19 is an enlarged schematic lateral side view of the expansionelement of FIG. 16 in accordance with one embodiment of the invention;

FIG. 20 is a schematic perspective view of the expansion element of FIG.16 in accordance with one embodiment of the invention;

FIG. 21A is an exploded schematic perspective view of a motor andcushioning element for an article of footwear including an intelligentsystem, in accordance with one embodiment of the invention;

FIG. 21B is a schematic perspective view of the assembled motor andcushioning element of FIG. 21A;

FIG. 22 is an exploded schematic perspective view of a motor andgearbox, in accordance with one embodiment of the invention;

FIG. 23A is a schematic side view of a sole and user input for anarticle of footwear including an intelligent system, in accordance withone embodiment of the invention;

FIG. 23B is a schematic side view of the sole of FIG. 23A with analternative user input;

FIG. 24 is an exploded schematic perspective view of an article offootwear including an intelligent system and further including a crashtransition element, in accordance with one embodiment of the invention;

FIG. 25A is a schematic perspective view of a sole for an article offootwear including an intelligent system, in accordance with oneembodiment of the invention;

FIG. 25B is an exploded schematic perspective view of the sole of FIG.25A;

FIG. 26 is a block diagram of an intelligent system in accordance withthe invention;

FIG. 27 is a flow chart depicting one mode of operation of theintelligent system of FIG. 1;

FIG. 28 is a flow chart depicting an alternative mode of operation ofthe intelligent system of FIG. 1;

FIG. 29 is a flow chart of a method for processing user inputs using theintelligent system of FIG. 1 in accordance with one embodiment of theinvention;

FIG. 30 is a flow chart of a method for measuring a sensor signal usingthe intelligent system of FIG. 1 in accordance with one embodiment ofthe invention;

FIG. 31 is a flow chart of a method for determining whether a sole of anarticle of footwear has compressed using the intelligent system of FIG.1 in accordance with one embodiment of the invention;

FIG. 32 is a flow chart of a method for monitoring the sensor signal todetect a compression in a sole of an article of footwear using theintelligent system of FIG. 1 in accordance with one embodiment of theinvention;

FIG. 33 is a flow chart of a method for determining whether anadjustment of a sole of an article of footwear is required using theintelligent system of FIG. 1 in accordance with one embodiment of theinvention;

FIG. 34 is a flow chart depicting an alternative mode of operation foran intelligent system in accordance with one embodiment of theinvention;

FIG. 35 is a circuit diagram of one embodiment of the intelligent systemof FIG. 1 for a left shoe;

FIG. 36 is a circuit diagram of one embodiment of the intelligent systemof FIG. 1 for a right shoe;

FIG. 37 is a table that lists the states of the input/output at certainpins of the microcontroller of FIG. 35 that are required to turn onseveral combinations of the electro-luminescent elements of FIG. 35;

FIG. 38 is a table that lists the output that is required at certainpins of the microcontroller of FIG. 35 to drive the motor of theintelligent system;

FIG. 39A is a schematic side view of an article of footwear including analternative embodiment of an intelligent system in accordance with theinvention;

FIG. 39B is a schematic perspective view of a portion of the intelligentsystem of FIG. 39A;

FIG. 40A is a schematic side view of an article of footwear includingyet another alternative embodiment of an intelligent system inaccordance with the invention;

FIGS. 40B-40D are schematic side views of the intelligent system of FIG.40A in various orientations;

FIG. 41A is a schematic side view of an article of footwear includingyet another alternative embodiment of an intelligent system inaccordance with the invention;

FIG. 41B is a schematic side view of the intelligent system of FIG. 41Athroughout a range of adjustment;

FIG. 42 is a graph depicting a performance characteristic of a specificembodiment of an adjustable element;

FIG. 43 is a flow chart depicting one embodiment of a method ofmodifying a performance characteristic of an article of footwear duringuse;

FIGS. 44A and 44B are flow charts depicting additional embodiments ofthe method of FIG. 43; and

FIG. 45 is a flow chart depicting one embodiment of a method ofproviding comfort in an article of footwear.

DETAILED DESCRIPTION

Embodiments of the present invention are described below. It is,however, expressly noted that the present invention is not limited tothese embodiments, but rather the intention is that modifications thatare apparent to the person skilled in the art are also included. Inparticular, the present invention is not intended to be limited to anyparticular performance characteristic or sensor type or arrangement.Further, only a left or right shoe is depicted in any given figure;however, it is to be understood that the left and right shoes aretypically mirror images of each other and the description applies toboth left and right shoes. In certain activities that require differentleft and right shoe configurations or performance characteristics, theshoes need not be mirror images of each other.

FIG. 1 depicts an article of footwear 100 including an upper 102, a sole104, and an intelligent system 106. The intelligent system 106 islaterally disposed in a rearfoot portion 108 of the article of footwear100. The intelligent system 106 could be disposed anywhere along thelength of the sole 104 and in essentially any orientation. In oneembodiment, the intelligent system 106 is used to modify thecompressibility of a heel area of the article of footwear 100. Inanother embodiment, the intelligent system 106 can be located in aforefoot portion 109 and can be moved into and out of alignment with aflex line or otherwise configured to vary a push-off characteristic ofthe footwear 100. In yet another embodiment, the footwear 100 couldinclude multiple intelligent systems 106 disposed in multiple areas ofthe footwear 100. The intelligent system 106 is a self-adjusting systemthat modifies one or more performance characteristics of the article offootwear 100. The operation of the intelligent system 106 is describedin detail hereinbelow.

FIG. 2A depicts an exploded view of a portion of the sole 104 of FIG. 1.The sole 104 includes a midsole 110, an outsole 112 a, 112 b, anoptional lower support plate 114, an optional upper support plate 116,and the intelligent system 106. The upper and lower support plates may,among other purposes, be included to help constrain the intelligentsystem 106 in a particular orientation. The intelligent system 106 isdisposed within a cavity 118 formed in the midsole 110. In oneembodiment, the midsole 110 is a modified conventional midsole and has athickness of about 10 mm to about 30 mm, preferably about 20 mm in theheel portion. The intelligent system 106 includes a control system 120and an actuation system 130 in electrical communication therewith, bothof which are described in greater detail hereinbelow. The actuationsystem 130 includes a driver 131 and an adjustable element 124. Thecontrol system 120 includes a sensor 122, for example a proximitysensor, a magnet 123, and electrical circuitry (see FIGS. 29-30). In theembodiment shown, the sensor 122 is disposed below the adjustableelement 124 and the magnet 123 is vertically spaced from the sensor 122.In this particular embodiment, the magnet 123 is disposed above theadjustable element 124 and is a Neodymium Iron Bore type magnet. Theactual position and spacing of the sensor 122 and magnet 123 will varyto suit a particular application, for example, measuring and modifyingthe compressibility of the sole. In this particular embodiment, thesensor 122 and magnet 123 are located in a spot that correspondsgenerally to where maximum compression occurs in the rearfoot portion108 of the footwear 100. Typically, the spot is under the wearer'scalcaneous. In such an embodiment, the sensor 122 and magnet 123 aregenerally centered between a lateral side and a medial side of the sole104 and are between about 25 mm and about 45 mm forward of a posterioraspect of the wearer's foot.

FIG. 2B depicts a portion of the intelligent system 106, in particularthe actuation system 130, in greater detail. The intelligent system 106is preferably encased in a sealed, waterproof enclosure. The actuationsystem 130 generally includes a driver 131, which includes a motor 132and a transmission element 134, and an adjustable element 124, whichincludes a limiter 128, an expansion element 126, and a stop 136. Theembodiment of the particular driver 131 shown is a lead screw drive,made up of a bi-directional electric motor 132 and a threaded rod thatforms the transmission element 134. In one embodiment, the motor 132 canbe a radio-controlled servomotor of the type used in model airplanes.The threaded rod could be made of steel, stainless steel, or othersuitable material.

The motor 132 is mechanically coupled to the transmission element 134and drives the element 134 in either a clockwise or counter-clockwisedirection as indicated by arrow 138. The transmission element 134threadedly engages the limiter 128 and transversely positions thelimiter 128 relative to the expansion element 126, as shown generally byarrow 140. Because the limiter 128 is threadedly engaged with thetransmission element 134 and prevented from rotation relative to themotor 132 and the footwear 100, no power is required to maintain thelimiter's position. There is sufficient friction in the actuation system130 and a sufficiently fine thread on the transmission element 134 toprevent inadvertent rotation of the element 134 during a heel strike. Inone example, the limiter 128 advances toward the expansion element 126(forward) when the motor 132 drives the transmission element 134 in theclockwise direction and the limiter 128 moves away from the expansionelement 126 (backward) when the motor 132 drives the transmissionelement 134 in the counter-clockwise direction. Alternatively, othertypes of drivers are possible. For example, the driver 131 could beessentially any type of rotary or linear actuator, a gear train, alinkage, or combinations thereof.

The expansion element 126 is generally cylindrical, with an elongatedcircular or elongated generally elliptically-shaped cross-section, or itincludes a series of arched walls with different centers, but identicalradii, or any combination thereof. The arcuate ends of the expansionelements are not necessarily semi-circular in shape. The radius of thearcuate ends will vary to suit a particular application and can bevaried to control the amount of longitudinal expansion of the expansionelement 126 when under compressive loading vertically. In general, thelarger the radius of the arcuate end, the greater longitudinal expansionis possible under vertical compression loading. The expansion element126 has a solid outer wall 142 and a optional compressible core 144 offoam or other resilient material. The size, shape, and materials used inthe expansion element 126 will be selected to suit a particularapplication. In the embodiment shown, the transmission element 134extends through the expansion element 126 and connects to a stop 136.The stop 136 prevents movement of the expansion element 126 in adirection away from the limiter 128. Alternatively, the stop 136 couldbe a rear wall of the cavity 118.

The general operation of the adjustable element 124 is described withrespect to an application where the intelligent system 106 is used tomodify cushioning in the article of footwear 100 in response to ameasured parameter, for example compression of the midsole 110. Theexpansion element 126 is allowed to compress when acted on by a verticalforce, depicted generally by arrows 146. The expansion element 126expands in the horizontal direction (arrow 148) when compressed. Thelimiter 128 is used to control this movement. As the horizontal movementis limited, the vertical movement is limited as well. The expansionelement 126 has a bi-modal compression response, which is discussed ingreater detail below with respect to FIG. 42.

The intelligent system 106 can control the amount of compression a usercreates in the article of footwear 100. As an example, when a userwearing the article of footwear 100 engages a ground surface during astride, the vertical force 146 is applied to the expansion element 126via the sole 104. The force 146 causes the expansion element 126 toexpand during ground contact until it contacts the limiter 128, therebycontrolling the compression of the sole 104.

During compression, the sensing portion of the control system 120measures field strength of the magnet 123. In the embodiment shown, thesensor 122 is disposed proximate the bottom of the midsole 110 and themagnet 123 is disposed proximate the top of the midsole 110. Themagnetic field strength detected by the sensor 122 changes as the magnet123 moves closer to the sensor 122, as the midsole 110 is compressed.The system can be calibrated, such that this magnetic field strength canbe converted to a distance. It is the change in distance that indicateshow much the midsole 110 has been compressed. The control system 120outputs a signal to the actuation system 130 based on the change indistance or compression measurement.

The actuation system 130 then modifies the hardness or compressibilityof the midsole 110 based on the signal received from the control system120. The actuation system 130 utilizes the transmission element 134 asthe main moving component. The operation of the intelligent system 106is described in greater detail below, with respect to the algorithmsdepicted in FIGS. 22-28.

FIG. 3 depicts a portion of an alternative embodiment of an intelligentsystem 306 in accordance with the invention, in particular the actuationsystem 330. The actuation system 330 includes a driver 331 and anadjustable element 324. The adjustable element 324 includes an expansionelement 326 and limiter 328 similar to that described with respect toFIG. 2B. The driver 331 includes a motor 332 and a transmission element334, in this embodiment a hollow lead screw 325 through which a cable327 passes. The cable 327 runs through the expansion element 326 and hasa stop 336 crimped to one end. The limiter 328 is a generallycylindrically-shaped element that is slidably disposed about the cable327 and acts as a bearing surface between the screw 325 and theexpansion element 326, in particular a bearing arm 339 coupled to theexpansion element 326. A similar bearing arm is disposed proximate thestop 336, to distribute loads along the depth of the expansion element326. In one embodiment, the motor 332 is a 8-10 mm pager motor with a50:1 gear reduction. The cable 327, screw 325, limiter 328, and bearingarm 339 may be made of a polymer, steel, stainless steel, or othersuitable material. In one embodiment, the cable 327 is made fromstainless steel coated with a friction-reducing material, such as thatsold by DuPont under the trademark Teflon®.

In operation, the cable 327 is fixedly attached to the driver 331 andhas a fixed length. The cable 327 runs through the screw 325, whichdetermines the amount of longitudinal travel of the expansion element326 that is possible. For example, as a vertical force is applied to theexpansion element 326, the element 326 expands longitudinally along thecable 327 until it hits the limiter 328, which is disposed between theexpansion element 326 and the end of the screw 325. The motor 332rotates the screw 325 to vary the length of the cable 327 that thelimiter 328 can slide along before contacting the screw 325 andexpansion element 326. The screw 325 moves a predetermined distanceeither towards or away from the element 326 in response to the signalfrom the control system. In one embodiment, the screw 325 may travelbetween about 0 mm to about 20 mm, preferably about 0 mm to about 10 mm.

In an alternative embodiment, the adjustable element 324 includes twomotors 332 and cables 327 oriented substantially parallel to oneanother. Two cables 327 aid in holding the expansion element 326 squarerelative to a longitudinal axis 360 of the adjustable element 324depicted in FIG. 3. In addition, other types of expansionelement/limiter arrangements are possible. For example, acircumferential or belly band type limiter may be used instead of adiametral or longitudinal type limiter. In operation, the driver 331varies the circumference of the belly band to vary the range ofexpansion of the element 326, the larger the circumference, the largerthe range of expansion. Other possible arrangements include shape memoryalloys and magnetorheological fluid.

FIGS. 4A-4E depict alternative adjustable elements, with each shown inan unloaded state. In particular, FIGS. 4A-4D depict certain differentpossible shapes for the expansion element. In FIG. 4A, the expansionelement 426 includes two cylinders 428 having generallyelliptically-shaped cross-sections and formed as a single element.Alternatively, the cylinder cross-sectional shape could be anycombination of linear and arcuate shapes, for example, hexagonal orsemi-circular. The cylinders 428 include a wall 432 and a pair of cores434 that may be hollow or filled with a foam or other material. FIG. 4Bdepicts an expansion element 446 having two separate cylinders 448having generally circular cross-sections and coupled together. Thecylinders 448 each have a wall 452 and a core 454. FIG. 4C depicts anexpansion element 466 including two cylinders 448 as previouslydescribed. In FIG. 4C, the expansion element 466 includes a foam block468 surrounding the cylinders 448. The foam block 468 may replace thecore or be additional to the core. FIG. 4D depicts yet anotherembodiment of an expansion element 486. The expansion element 486includes a cylinder 488 having an elongate sector cross-sectional shape.The cylinder includes a wall 492 and a core 494. The cylinder 488includes a first arcuate end 496 and a second arcuate end 498. The firstarcuate end 496 has a substantially larger radius than the secondarcuate end 498, thereby resulting in greater horizontal displacement atthe first arcuate end when under load. Additionally, the wall thicknessof any cylinder can be varied and/or the cylinder could be tapered alongits length. In embodiments of the expansion element 126 that use a foamcore, it is undesirable to bond the foam core to the walls of theexpansion element 126. Bonding the foam to the walls may inhibithorizontal expansion.

FIG. 4E depicts an alternative type of adjustable element 410. Theadjustable element 410 includes a relatively flexible structuralcylinder 412 and piston 414 arrangement. The internal volume 416 of thecylinder 412 varies as the piston 414 moves into and out of the cylinder412, shown generally by arrow 418. The piston 414 is moved linearly bythe driver 131 in response to the signal from the control system 120. Byvarying the volume 416, the compressibility of the cylinder 412 isvaried. For example, when the piston 414 is moved into the cylinder 412,the volume is reduced and the pressure within the cylinder is increased;the greater the pressure, the harder the cylinder. While this system mayappear similar to that of an inflatable bladder, there are differences.For example, in this system, the amount of fluid, e.g., air, staysconstant, while the volume 416 is adjusted. Further, bladders primarilyreact based on the pressure within the bladder, whereas the element 410depicted in FIG. 4E uses the structure of the cylinder in combinationwith the internal pressure. The two are fundamentally different inoperation. For example, the inflatable bladder, like a balloon, merelyholds the air in and provides no structural support, while the cylinder,like a tire, uses the air to hold up the structure (e.g. the tiresidewalls). In addition, the piston 414 and driver 131 arrangementallows for fine adjustment of the pressure and compressibility of theadjustable element 410.

FIG. 5A depicts a side view of the article of footwear 100 of FIG. 1.The intelligent system 106 is disposed generally in the rearfoot portion108 of the article of footwear 100. As shown in FIG. 5A, the intelligentsystem 106 includes the adjustable element 124 with the limiter 128 andthe driver 131. Also shown is a user-input module 500 (FIG. 5B)including user-input buttons 502, 504 and an indicator 506. The user canset the compression range or other performance characteristic targetvalue of the article of footwear 100, by pushing input button 502 toincrease the target value or pushing input button 504 to decrease thetarget value or range. In an alternative embodiment, the user-inputmodule 500 can be remotely located from the shoe. For example, awristwatch, personal digital assistant (PDA), or other externalprocessor could be used alone or in combination with the user-inputmodule 500 disposed on the article of footwear, to allow the user tocustomize characteristics of the intelligent system 106. For example,the user may press buttons on the wristwatch to adjust differentcharacteristics of the system 106. In addition, the system 106 mayinclude an on and off switch.

The user-input module 506 is shown in greater detail in FIG. 5B. Theindicator(s) 506 may be one or more electro-luminescent elements, forexample. In the embodiment shown, the indicator 506 is a series ofelectro-luminescent elements printed on a flex-circuit that glow toindicate the range of compression selected; however, the indicatorscould also indicate the level of hardness of the midsole or some otherinformation related to a performance characteristic of the footwear 100.Alternatively or additionally, the indicator may be audible.

FIG. 6 depicts a top view of one possible arrangement of selectcomponents of the intelligent system of FIG. 1. The adjustable element124 is disposed in the rearfoot portion 108 of the midsole 110 with theexpansion element 126 laterally disposed within the cavity 118. Thedriver 131 is disposed adjacent to the expansion element 126. Adjacentto the driver 131 is the control system 120. The control system 120includes a control board 152 that holds a micro-controller forcontrolling the driver 131 and for processing the algorithm. Further,the system 106 includes a power source 150, for example a 3.0V ½ AAbattery. The power source 150 supplies power to the driver 131 and thecontrol system 120 via wires 162 or other electrical connection, such asa flexcircuit.

The system 106 further includes the magnet 123 and the aligned sensor122 (not shown), which is located under the expansion element 126 and iselectrically coupled to the control system 120. The magnet 123 islocated above the expansion element 126, but below an insole and/or sockliner. Further, the entire intelligent system 106 can be built into aplastic casing to make the system 106 waterproof. In addition, thesystem 106 can be built as a single module to facilitate fabrication ofthe sole 104 and may be pre-assembled to the lower support plate 114(not shown in FIG. 6). In one embodiment, the system 106 is removable,thereby making the system 106 replaceable. For example, the outsole 112a, 112 b may be configured (e.g., hinged) to allow the system to beremoved from the cavity 118 of the midsole 110.

The system 106 may also include an interface port 160 that can be usedto download data from the intelligent system 106, for example to a PDAor other external processor. The port 106 can be used to monitor shoeperformance. In an alternative embodiment, the data can be transmitted(e.g., via radio waves) to a device with a display panel located withthe user. For example, the data can be transmitted to a wristwatch orother device being worn the user. In response to the data, the user mayadjust certain characteristics of the shoe by pressing buttons on thewristwatch, as described above. These adjustments are transmitted backto the system 106 where the adjustments are implemented.

FIG. 7 depicts an exploded perspective view of a sole 204 of the articleof footwear 100 of FIG. 1 in accordance with another embodiment of theinvention. The sole 204 includes a midsole 210, an outsole 212, anoptional lower support plate 214, and an optional upper support plate216. A rearfoot portion 208 of the sole 204 may be made from, forexample, a foam, such as a polyurethane (PU) or ethylene vinyl acetate(EVA) foam, and may be adapted to receive an expansion element 226. Inone embodiment, the expansion element 226 is, as shown, shaped like ahoneycomb; however, the element 226 may also be generally cylindrical,with an elongated circular or elongated generally elliptically-shapedcross-section, or include a series of arched walls with differentcenters, but identical radii, or any combination thereof. A motor 232 isalso positioned within the sole 204 and may be used to adjust theexpansion element 226. A user interface 254, including user inputbuttons 256, may also be provided for receiving user inputs related tothe adjustment of the sole 204.

FIGS. 8A-8G depict perspective views of various components that may beincluded in various embodiments of the sole 204. The components includethe motor 232 (FIG. 8A), the expansion element 226 (FIG. 8B), theoptional lower support plate 214 (FIG. 8C), the user interface 254 andthe user input buttons 256 (FIG. 8D), the rearfoot portion 208 that maybe made from, for example, the PU or EVA foam (FIG. 8E), the optionalupper support plate 216 (FIG. 8F), and the midsole 210 (FIG. 8G).

FIG. 9 depicts a bottom view of the midsole 210 of FIGS. 7 and 8G. Themidsole 210 includes an opening 257 for accessing the power source 150(see FIG. 6) and related equipment used in the intelligent system 106.The position of the opening 257 in the midsole 210 can vary depending onthe location of the power source 150 and related equipment in the sole204.

FIG. 10 depicts a bottom view of an optional torsional bar 258 that maybe used with the sole 204 of FIG. 7 in accordance with one embodiment ofthe invention. The torsional bar 258 may include openings 264 a, 264 bat the heel and at the shank. The openings 264 may provide clearancefor, or access to, the various components of the intelligent system 106.

FIG. 11 depicts a bottom view of the optional torsional bar 258 of FIG.10 disposed on the midsole 210 illustrated in FIG. 9 in accordance withone embodiment of the invention. The opening 264 b on the torsional bar258 aligns with the opening 257 in the midsole 210 to enable a user toaccess the power source 150 and related equipment in the sole 204.

FIG. 12 depicts a bottom view of the midsole 210 and the optionaltorsional bar 258 of FIG. 11, further including additional heel foamelements 266 a, 266 b, 266 c in accordance with one embodiment of theinvention. The illustrated embodiment includes three heel foam elements:(1) a rear foam element 266 a extending from a medial to a lateral sideof the midsole 210; (2) a medial front foam 266 b element; and (3) alateral front foam element 266 c. The hardness of the foam elements 266may vary to suit a particular application. For example, the lateralfront foam element 266 c may be harder than the rear foam element 266 a.The material properties may vary between and within the different foamelements 266 to perform different functions, for example, to guide thefoot into a neutral position between pronation and supination during astep cycle. The use of foam elements for cushioning and guidance isdescribed in greater detail in U.S. Pat. No. 6,722,058 and U.S. patentapplication Ser. No. 10/619,652, the disclosures of which are herebyincorporated by reference herein in their entireties. Details ofadditional structural elements that can be used in an article offootwear with an intelligent system are described in greater detail inU.S. patent application Ser. No. 11/346,998, the disclosure of which ishereby incorporated by reference herein in its entirety.

FIG. 13 depicts a bottom view of the midsole 210 and the optionaltorsional bar 258 of FIG. 11, further including the motor 232 and thepower source 150 disposed in the openings 257, 264 b that extend throughthe midsole 210 and optional torsional bar 258, the user interface 254,and the expansion element 226 in accordance with one embodiment of theinvention. Alternatively or additionally, the expansion element 226could be located in the forefoot area of the sole 204, or atsubstantially any position along the sole 204. In addition, theorientation of the expansion element 226 in the sole 204 can be variedto suit a particular application. For example, in one embodiment, theintelligent system could be located on only the medial or lateral sideto provide a controlled dual density sole, one part of which would beautomatically adjustable.

FIG. 14 depicts a bottom view of the midsole 210 of FIG. 13 furtherincluding the additional heel foam elements 266 a, 266 b, 266 c of FIG.12 in accordance with one embodiment of the invention. In theillustrated embodiment, the expansion element 226 is shown embeddedbetween the three foam elements 266 a, 266 b, 266 c.

FIG. 15 depicts a bottom view of the midsole 210 of FIG. 14 furtherincluding a casing 270 that covers the power source 150 and otherelectronic components in accordance with one embodiment of theinvention. The casing 270 can optionally be removed to enable a user toaccess the power source 150 and other electronic equipment.

FIG. 16 is a lateral perspective view of the sole 204 including thehoneycombed shaped expansion element 226 and the user interface 254 thatmay be used to alter the settings of the intelligent system 106 inaccordance with one embodiment of the invention. In various embodiments,the sole 204 can include multiple expansion elements 226. A cableelement (not shown) may extend between the medial front foam element 266b and the lateral front foam element 266 c, and also between the rearfoam elements 266 a. The expansion elements 226 can be coupled togetherby the cable passing therethrough. The user interface 254 includesbuttons 256 to increase (+) and/or decrease (−) the performancecharacteristic(s) of the intelligent system 106 and electro-luminescentelements 268 to indicate the system setting.

FIG. 17 is a lateral side view of the sole 204 of FIG. 16, where theexpansion element 226 is more fully illustrated. The expansion element226 is, as shown, shaped like a honeycomb; however, the element 226 mayalso be generally cylindrical, with an elongated circular or elongatedgenerally elliptically-shaped cross-section, or include a series ofarched walls with different centers, but identical radii, or anycombination thereof.

FIG. 18 is an enlarged lateral view of the user interface 254 of FIG. 16illustrating the buttons 256 that are used to increase (+) and/ordecrease (−) the performance characteristic(s) provided by theintelligent system 106 and the electro-luminescent elements 268 thatindicate the system setting in accordance with one embodiment of theinvention.

FIG. 19 is an enlarged lateral side view of the expansion element 226 ofFIG. 16 illustrating its honeycomb shape in accordance with oneembodiment of the invention. In addition, a cable 327 is shown runningthrough the middle of the expansion element 226.

FIG. 20 depicts a perspective view of the expansion element 226 of FIG.16 in accordance with one embodiment of the invention. The expansionelement 226 has four generally vertical side walls 272 (two on eachside), whereby a generally horizontal bar 274 connects the adjacent sidewalls 272 on each side to each other, thereby forming the generallyhoneycomb-like structure. The horizontal bar 274 is generally centrallydisposed between the side walls 272. The horizontal bars 274 providestability against shear forces in a longitudinal direction and in someinstances may be under tension. In one embodiment, the side walls 272have a generally arcuate shape; however, the side walls 272 and thehorizontal bar 274 can be linear, arcuate, or combinations thereof. Theexpansion element 226 may also include a top bar 276 and a bottom bar278.

FIG. 21A depicts one example of a motor and cushioning element assemblyfor an article of footwear including an intelligent system. Thearrangement 3000 includes a cushioning element 3010 that is connected bya cable assembly 3020 to a gear arrangement 3030 and a motor 3040. Themotor 3040 and gear arrangement 3030 are housed in a gearbox 3050, whichis in turn housed within a main housing 3060. The main housing 3060 canhold a battery 3070 in place by, for example, a clip 3080. An O-ring3090 and battery lid 3100 can then be mounted on the housing 3060 andcan provide a waterproof seal over the battery 3070, thus protecting themotor 3040, gearbox 3050, and associated electronics from any damagingmoisture or other contaminants, such as, but not limited to, water, mud,dust, and perspiration.

The motor 3040, gearbox 3050, and associated electronics can be furtherprotected from the elements by a gasket 3110 and an end cover 3120. AnO-ring 3170 can be placed on a ferrule 3160, covering the cable assembly3020, to provide a waterproof seal to stop contaminants from enteringthe gearbox 3050 around the cable assembly 3020. The cable assembly 3020can then be inserted through the cushioning element 3010 and held inplace by crossbars 3130 and 3140. Upon assembling the arrangement 3000,the cushioning element 3010 can be adjusted through signals from acontrol system connected to the motor 3040 by electrical circuitry 3180.A magnet 3150 can be used, in an example embodiment, to provide a meansof obtaining a signal relating to the compression of the cushioningelement 3010, as described previously.

Providing O-rings, a gasket, and, end covers for the gearbox 3050, cableassembly 3020, and battery compartment allows the motor and gearassembly to be maintained waterproof. This can be advantageous inprotecting the gearbox arrangement from the elements, including water,mud, dust, sand, or other contaminants that an athletic shoe may beexposed to. The waterproof arrangement can also protect the gearbox frommoisture generated through perspiration by the shoe's wearer. Thisprotection will result in an extension of the working life of theassembly and a possible increase in the efficiency of the assembly.

The assembled motor and cushioning element arrangement 3000 can be seenin FIG. 21B. As can be seen, the cable assembly 3020 connects thecushioning element 3010 to the gearbox 3050 housed in the main housing3060. The gasket 3110 and end covering 3120 provide protection for thegearbox 3050 and the motor 3040. The electrical circuitry 3180 connectsto the battery 3070, the motor 3040, and associated electronics withinthe main housing 3060, and to a sensor embedded within the cushioningelement 3010.

An exploded view of the gearbox 3050, motor 3040, and gear arrangement3030 can be seen in FIG. 22. Also shown are the main axle 3020, and asecondary axle 3200 for elements of the gear arrangement 3030. A sensingmeans 3190 can be placed on the motor assembly to provide a means ofaccurately determining the rotation of the shaft 3210 of the motor 3040,or the rotation of a gear or other rotating component. In oneembodiment, the sensing means 3190 can be a magnetic sensor or a magnetattached to a separate sensor located on the electrical circuitry 3180,with the location of the sensing means 3190 corresponding to thelocation of a magnet positioned on the shaft 3210. This arrangementallows the sensing means 3190 to accurately determine the number ofrevolutions and/or angular position of the shaft 3210, with the sensingmeans 3190 recognizing a full rotation of the shaft 3210 every time themagnet placed upon the shaft 3210 passes next to the sensing means 3190.The sensing means 3190 can also be used to determine the rotation of agear, or other rotating component. In alternative embodiments, differentmeans of determining the rotation of the shaft 3210 can be used, suchas, but not limited to, employing a mechanical, electrical, or opticalsensor to measure a full or partial rotation of the shaft 3210.

One embodiment of a sole and user input for an article of footwearincluding an intelligent system is shown in FIG. 23A. In thisembodiment, a user input housing 3320 is mounted to a sole unit 3310.The user input housing 3320 provides a means for a wearer to adjust thesettings for the cushioning element embedded within the sole 3310. Inone embodiment, the user input can include two buttons embedded withinthe user input housing 3320. These buttons can allow the wearer to inputa positive input 3340 and/or a negative input 3330 into the controllerof the cushioning element. For example, a positive input 3340 may beused to increase the user preferred stiffness of a cushioning element,while a negative input 330 may be used to decrease the user preferredstiffness of the cushioning element. In one alternative embodiment, thepositive input 3340 and negative input 3330 can be used to increase ordecrease a threshold compression that determines when the motor andcontroller automatically adjust the resistance of the cushioningelement. In further embodiments, pushing one or more of these buttonsmay be used to turn the motor and controller on and/or off, set thecontroller to run a different control algorithm, or adjust anotherelement of the controller and/or motor function.

In a further alternative embodiment, the positive input 3340 andnegative input 3330 can be replaced by a single capacitive userinterface running between a positive end and negative end of the userinput housing 3320. This interface may be, for example, resistance basedor capacitance based. In this embodiment, adjustment of the cushioning,or any other user defined input described above, can be enabled bysliding a digit along the user input in either a positive or negativedirection, in a manner similar to that used to control touch sensitivecomputer mousepads or by simply touching the user interface in a certainlocation such as on the “+” or “−”. Further alternative user inputs mayinclude a dial, slider, or other appropriate input mechanism.

FIG. 23B shows an alternative sole and user input for an article offootwear including an intelligent system. In this embodiment, analternative user input housing 3350 is attached to the sole 3310. Inthis embodiment, the user input includes a substantially circular oroval capacitive user interface that provides a signal to the controlsystem through movement of a user's digit over the surface of theinterface. Here, a positive adjustment of the stiffness can be providedby a clockwise rotation 3370 of the digit over the surface of theinterface, while a negative adjustment of the stiffness can be providedby a counter-clockwise rotation 3380 of a user's digit over theinterface surface. As described above, the interface can be set toadjust a variety of parameters of the control system and motor,depending upon the requirements of the user or the particular shoe.

Multiple input mechanisms are also contemplated. For example, thecircular or oval capacitive user interface can be combined with afurther, separate input 3380 to provide the user with greater control ofthe system and motor. The input 3380 can include any of the userinterface mechanisms described above.

An exploded view of an article of footwear 3400 including an intelligentsystem can be seen in FIG. 24. This embodiment includes a top plate 3450that is attached to the upper 3460 of the article of footwear 3400 andhouses a motor 3470 and other elements of the intelligent system. Anumber of elliptical structures 3480 are over molded onto the top plate3450 to provide cushioning to the forefoot area of the sole of thearticle of footwear 3400. A bottom plate 3490 can then be molded, orotherwise fitted, to the elliptical structures 3480 and/or other soleelements to complete the sole of the article of footwear 3340.

This example embodiment also includes a crash transition element 3430that is surrounded by two independently tuned guidance structures 3440.The crash transition element 3430 and guidance structures 3440 arelocated in the heel region of the article of footwear. In oneembodiment, the crash transition element 3430 is a structural cushioningelement, the compressibility of which can be adjusted by the intelligentsystem 106. Alternatively, the crash transition element 3430 can be astructural element that can be adjusted to affect other performancecharacteristics of the shoe. Further, the crash transition element 3430can be configured to respond rapidly to a signal from the intelligentsystem 106.

This embodiment includes a further alternative user input interface3410, including two buttons providing a positive and negative userinput. The user input interface 3410 can also include a series of LEDs3420, what can provide the user with a visual indication of the settingof the cushioning control system. This user input interface can bereplaced, in alternative embodiments, by any of the user inputsdescribed previously.

FIG. 25A shows a partially exploded schematic perspective view of thesole of an article of footwear including an intelligent system, for usewith a basketball shoe. In this embodiment, the sole 3500 includes abattery 3510, a motor and gear assembly 3520, and a cushioning element3530, all embedded within a molded sole 3540. In this configuration, thebattery 3510 is placed in front of the motor and gear assembly 3520,rather than on top of the motor assembly. This placement of the battery3510 can decrease the overall height of the system, allowing the controlsystem to be embedded in thinner soles. This can be advantageous inshoes such as those required for basketball, indoor soccer, squash, orother aerobic activities, where it is preferable to have a thinner solein order to place the wearer's foot closer to the ground to facilitateturning, jumping, landing, cutting, starting and stopping rapidly, andother movements with such activities.

In this configuration, the battery 3510 is placed in front of the motorand gear assembly 3520 in the midsole region of the molded sole 3540. Itmay be advantageous to place the battery in this region as in manyactivities it is subject to lower compressive loads than the heel andforefoot regions of the sole. The battery compartment can be accessedthrough the upper side of the molded sole 3540 in order to insert andreplace a battery 3510 when required. In alternative embodiments, thebattery compartment can be accessed through the bottom or a side of themolded sole 3540.

In alternative embodiments of the invention, the battery 3510 can beplaced at a number of different locations within the sole or upper of anarticle of footwear including an intelligent system, depending upon thespecific shoe design and user requirements. For example, compartmentsfor the battery, or batteries, can be placed at locations including, butnot limited to, the forefoot or heel portions of the sole, on the sideof the sole, on the rear of the shoe at the heel, or at a location onthe upper of the shoe.

FIG. 25B is an exploded view of the sole of FIG. 25A. The sole 3500includes an outsole 3550, a support element 3560, a lower support plate3570, a rearfoot portion 3580, an upper support plate 3590, and amidsole 3600. An adjustable expansion element 3610, a motor 3620, and apower source 3630 are embedded within the sole 3500 between the lowersupport plate 3570 and the midsole 3600. The power source 3630 can be abattery, or any other appropriate means for providing power to the motor3620. A user interface 3640 can be attached to a side of the assembledsole 3500 to provide a user with means of adjusting the functions of theexpansion element 3610 and motor 3620 assembly. A sensor 3650 and sensorcover 3660 can be located below the expansion element 3610.

Upon construction, the motor 3620 and the power source 3630 are insertedinto a cavity 3670 in the midsole 3600. In certain embodiments, accessto the power source 3630 can be gained through an opening in the uppersurface of the midsole 3600, while in other embodiments the power source3630 can be accessed through on opening on the bottom or side of thesole 3500. In further embodiments, one or more elements of the sole3500, such as the support element 3560, the lower support plate 3570, orthe upper support plate 3590, may not be required, depending upon thespecific style of shoe being constructed.

A block diagram of one embodiment of an intelligent system 706 is shownin FIG. 26. The intelligent system 706 includes a power source 750electrically coupled to a control system 720 and an actuation system730. The control system 720 includes a controller 752, for example oneor more micro-processors, and a sensor 722. The sensor may be aproximity-type sensor and magnet arrangement. In one embodiment, thecontroller 152 is a microcontroller such as the PICMicro®microcontroller manufactured by Microchip Technology Incorporated ofChandler, Ariz. In another embodiment, the controller 752 is amicrocontroller manufactured by Cypress Semiconductor Corporation. Theactuation system 730 includes a driver 731, including a motor 732 and atransmission element 734, and an adjustable element 724. The driver 731and control system 720 are in electrical communication. The adjustableelement 724 is coupled to the driver 731.

Optionally, the actuation system 730 could include a feedback system 754coupled to or as part of the control system 720. The feedback system 754may indicate the position of the adjustable element 724. For example,the feedback system 754 can count the number of turns of the motor 732or the position of the limiter 728 (not shown). The feedback system 754could be, for example, a linear potentiometer, an inductor, a lineartransducer, or an infrared diode pair.

FIG. 27 depicts one possible algorithm for use with the intelligentsystem 106. The intelligent system 106 measures a performancecharacteristic of a shoe during a walk/run cycle. Before the system 106begins to operate, the system 106 may run a calibration procedure afterfirst being energized or after first contacting the ground surface. Forexample, the system 106 may actuate the adjustable element 124 todetermine the position of the limiter 128 and/or to verify the range ofthe limiter 128, i.e., fully open or fully closed. During operation, thesystem 106 measures a performance characteristic of the shoe (step 802).In one embodiment, the measurement rate is about 300 Hz to about 60 KHz.The control system 120 determines if the performance characteristic hasbeen measured at least three times (step 804) or some otherpredetermined number. If not, the system 106 repeats step 802 by takingadditional measurements of the performance characteristic until step 804is satisfied. After three measurements have been taken, the system 106averages the last three performance characteristic measurements (step806). The system 106 then compares the average performancecharacteristic measurement to a threshold value (step 808). At step 810,the system 106 determines if the average performance characteristicmeasurement is substantially equal to the threshold value. If theaverage performance characteristic measurement is substantially equal tothe threshold value, the system 106 returns to step 802 to take anotherperformance characteristic measurement. If the average performancecharacteristic measurement is not substantially equal to the thresholdvalue, the system 106 sends a corrective driver signal to the adjustableelement 124 to modify the performance characteristic of the shoe. Theintelligent system 106 then repeats the entire operation until thethreshold value is reached and for as long as the wearer continues touse the shoes. In one embodiment, the system 106 only makes incrementalchanges to the performance characteristic so that the wearer does notsense the gradual adjustment of the shoe and does not have to adapt tothe changing performance characteristic. In other words, the system 106adapts the shoe to the wearer, and does not require the wearer to adaptto the shoe.

Generally, in a particular application, the system 106 utilizes anoptimal midsole compression threshold (target zone) that has beendefined through testing for a preferred cushioning level. The system 106measures the compression of the midsole 110 on every step, averaging themost recent three steps. If the average is larger than the thresholdthen the midsole 110 has over-compressed. In this situation, the system106 signals the driver 131 to adjust the adjustable element 124 in ahardness direction. If the average is smaller than the threshold, thenthe midsole 110 has under-compressed. In this situation, the system 106signals the driver 131 to adjust the adjustable element in a softnessdirection. This process continues until the measurements are within thetarget threshold of the system. This target threshold can be modified bythe user to be harder or softer. This change in threshold is an offsetfrom the preset settings. All of the above algorithm is computed by thecontrol system 120.

In this particular application, the overall height of the midsole 110and adjustable element 124 is about 20 mm. During testing, it has beendetermined that an optimal range of compression of the midsole 110 isabout 9 mm to about 12 mm, regardless of the hardness of the midsole110. In one embodiment, the limiter 128 has an adjustment range thatcorresponds to about 10 mm of vertical compression. The limiter 128, inone embodiment, has a resolution of less than or equal to about 0.5 mm.In an embodiment of the system 106 with user inputs, the wearer may varythe compression range to be, for example, about 8 mm to about 11 mm orabout 10 mm to about 13 mm. Naturally, ranges of greater than 3 mm andlower or higher range limits are contemplated and within the scope ofthe invention.

During running, the wearer's foot goes through a stride cycle thatincludes a flight phase (foot in the air) and a stance phase (foot incontact with the ground). In a typical stride cycle, the flight phaseaccounts for about ⅔ of the stride cycle. During the stance phase, thewearer's body is normally adapting to the ground contact. In aparticular embodiment of the invention, all measurements are takenduring the stance phase and all adjustments are made during the flightphase. Adjustments are made during the flight phase, because the shoeand, therefore, the adjustable element are in an unloaded state, therebyrequiring significantly less power to adjust than when in a loadedstate. In most embodiments, the shoe is configured such that the motordoes not move the adjustable element; therefore lower motor loads arerequired to set the range of the adjustable element. In the embodimentsdepicted in FIGS. 39, 40, and 41, however, the adjustable element doesmove, as described in greater detail hereinbelow.

During operation, the system 106 senses that the shoe has made contactwith the ground. As the shoe engages the ground, the sole 104 compressesand the sensor 122 senses a change in the magnetic field of the magnet123. The system 106 determines that the shoe is in contact with theground when the system 106 senses a change in the magnetic field equalto about 2 mm in compression. It is also at this time that the system106 turns off the power to the actuation system 130 to conserve power.During the stance phase, the system 106 senses a maximum change in themagnetic field and converts that measurement into a maximum amount ofcompression. In alternative embodiments, the system 106 may also measurethe length of the stance phase to determine other performancecharacteristics of the shoe, for example velocity, acceleration, andjerk.

If the maximum amount of compression is greater than 12 mm, then thesole 104 has over-compressed, and if the maximum amount of compressionis less than 9 mm, then the sole 104 has under-compressed. For example,if the maximum compression is 16 mm, then the sole 104 hasover-compressed and the control system 120 sends a signal to theactuation system 130 to make the adjustable element 124 firmer. Theactuation system 130 operates when the shoe is in the flight phase,i.e., less than 2 mm of compression. Once the system 106 senses that thecompression is within the threshold range, the system 106 continues tomonitor the performance characteristic of the shoe, but does not furtheroperate the actuation system 130 and the adjustable element 124. In thisway, power is conserved.

In alternative embodiments, the intelligent system 106 can useadditional performance characteristics alone or in combination with theoptimal midsole compression characteristic described above. For example,the system 106 can measure, in addition to compression, time to peakcompression, time to recovery, and the time of the flight phase. Thesevariables can be used to determine an optimum setting for the user,while accounting for external elements such as ground hardness, incline,and speed. Time to peak compression is described as the amount of timethat it takes from heel strike to the maximum compression of the solewhile accounting for surface changes. It may be advantageous to use thearea under a time versus compression curve to determine the optimumcompression setting. This is in effect a measure of the energy absorbedby the shoe. In addition, the time of the flight phase (described above)can contribute to the determination of the optimum setting. The stridefrequency of the user can be calculated from this variable. In turn,stride frequency can be used to determine changes in speed and todifferentiate between uphill and downhill motion.

FIG. 28 depicts another possible algorithm that may be performed by theintelligent system 106. In particular, FIG. 28 illustrates oneembodiment of a method 2300 for modifying a performance characteristicof the article of footwear 100 during use. At step 2500 of the method2300, the intelligent system 106 measures a sensor signal from thesensor 122. The intelligent system 106 then determines, at step 2600,whether the sole 104 has compressed. Alternatively or additionally, thesystem 106 can determine if the user has engaged in any of variousactivities, for example running, cutting, jumping, or landing, to whichthe system 106 can adjust a performance characteristic in responsethereto. Upon determining that the sole 104 has compressed, theintelligent system 106 performs initial calculations, at step 2700, todetermine whether an adjustment of the sole 104 is required. At step2800, the intelligent system 106 performs additional calculations todetermine further or alternatively whether an adjustment of the sole 104is required. If an adjustment of the sole 104 is required, theintelligent system 106 also adjusts the sole 104 at step 2800. FIGS. 25,26, 27, and 28, which follow, describe methods for implementing thesteps 2500, 2600, 2700, and 2800, respectively, of the method 2300.

The method 2300 begins by providing power to the intelligent system 106.For example, a battery may act as the power source 150 and may beinstalled in the intelligent system 106 at step 2304. Once the batteryis installed in the intelligent system 106, the intelligent system 106may run an “ON” sequence at step 2308. For example, the intelligentsystem 106 may light the electro-luminescent elements of the indicator506 in a manner that signals to a user of the article of footwear 100that the intelligent system 106 is active. Where the battery is alreadyinstalled in the intelligent system 106, but a user of the article offootwear 100 has previously turned the intelligent system 106 off (asdescribed below), the user may turn the intelligent system 106 on andactivate the “ON” sequence by pressing, for example, one or more of theuser-input buttons 502, 504 at step 2312.

Once the intelligent system 106 is on, the intelligent system 106 maycheck for user input at step 2316. In the embodiments depicted in FIGS.28-33, the user indicates a desire to increase hardness of the sole 104by pressing the “+” button 502, and a desire to decrease the hardness ofthe sole 104 (i.e., increase the softness of the sole 104) by pressingthe “−” button 504. If user input is received from a user of the articleof footwear 100, as determined at step 2320, the intelligent system 106processes the user input at step 2400. FIG. 29, which follows, describesa method implementing the step 2400 of the method 2300. If user input isnot received, the intelligent system 106 measures the sensor signal fromthe sensor 122 at step 2500.

Optionally, the method 2300 may include a self diagnostic and useranalysis/interaction step 2324. More specifically, at step 2324, theintelligent system 106 may diagnose itself by checking severalparameters of the intelligent system 106 described herein, including,but not limited to, the sensor condition and/or output, the batterystrength, the motor direction, the condition of the voltage referencethat may be used in step 2500, and the presence or absence of user-inputfrom buttons 502, 504. Moreover, at step 2324, a user of the article offootwear 100 may read data from the intelligent system 106 or performother functions. In one embodiment, a special key is used to access theintelligent system 106. For example, armed with their own special keys,retailers could read certain data, manufacturers could read other datauseful in, for example, preparing a failure report, and customers couldbe allowed to manually adjust the intelligent system 106 by, forexample, moving the motor 132. Additionally or alternatively, theintelligent system 106 may be able to track or monitor the athleticperformance of a wearer of the article of footwear 100, such as, forexample, the distance traveled by the wearer, the wearer's pace, and/orthe wearer's location. In such an embodiment, this information may beaccessed at step 2324.

In one embodiment, the intelligent system 106 cycles through the stepsof the method 2300 by following the directions of the arrows indicatedin FIG. 28, with each particular step along the way being performed ornot depending on the value of certain parameters. In addition, in oneparticular embodiment, the intelligent system 106 cycles through steps2316, 2320, 2500, 2324, 2600, 2700, and 2800 at a rate between about 300Hz and about 400 Hz.

In some embodiments, a microcontroller of the intelligent system 106performs many of the steps described with respect to FIGS. 28-33. Themicrocontroller may include, for example, a receiver that is configuredto receive a first signal representing an output from the sensor 122, adetermination module that is configured to determine whether the sole104 has compressed and to determine whether adjustment of the sole 104is required, and a transmitter that is configured to transmit a secondsignal for adjusting the sole 104.

In greater detail, if the intelligent system 106 determines, at step2320, that a user has entered input, the intelligent system 106processes such user input at step 2400. Referring to FIG. 29, whichdepicts one embodiment of a method 2400 for processing the user input,if the user has pressed both the “+” button 502 and the “−” button 504at the same time, as determined at step 2402, the intelligent system 106calls the “OFF” sequence at step 2404. Referring back to FIG. 28, theintelligent system 106 then runs the “OFF” sequence at step 2328. In oneembodiment, in running the “OFF” sequence, the intelligent system 106lights the electro-luminescent elements of the indicator 506 in a mannerthat signals to a user of the article of footwear 100 that theintelligent system 106 is being turned off. The intelligent system 106may then enter an “OFF” or “DEEP SLEEP” mode at step 2332 until it isagain activated by the user at step 2312.

Returning to FIG. 29, the sole 104 of the article of footwear 100 mayinclude a number of hardness settings, and the intelligent system 106may be configured to change the hardness setting for the sole 104 inresponse to receiving the user input. It should be noted, however, thatwhile the hardness setting for the sole 104 is a user adjustableparameter, changing the hardness setting for the sole 104 does notnecessarily lead to an adjustment of the sole 104 itself (e.g., asoftening or hardening of the sole 104). Whether or not the sole 104 isitself adjusted depends in part on the hardness setting, but also onmany other variables, and is not determined until steps 2700 and 2800described below. It should also be noted that the values of theconstants, settings, and other parameters can be varied as necessary tosuit a particular application of the shoe, for example for running orbasketball.

In one embodiment, the number of hardness settings for the sole 104 isbetween five and 20. If the user has pressed only the “−” button 504(decided at step 2406), the intelligent system 106 determines, at step2408, whether the current hardness setting for the sole 104 can bechanged to a softer setting. If so (i.e., if the hardness setting forthe sole 104 is not currently set to its softest setting), theintelligent system 106 changes the hardness setting for the sole 104 toa softer setting at step 2412. Similarly, if the user has pressed onlythe “+” button 502 (decided at step 2414), the intelligent system 106determines, at step 2416, whether the current hardness setting for thesole 104 can be changed to a harder setting. If so (i.e., if thehardness setting for the sole 104 is not currently set to its hardestsetting), the intelligent system 106 changes the hardness setting forthe sole 104 to a harder setting at step 2420.

Following the adjustment of the hardness setting for the sole 104 ateither step 2412 or step 2420, the intelligent system 106 calculates,either at step 2424 or at step 2428, at least one new threshold ofcompression in response to receiving the user input. In one embodiment,the intelligent system 106 calculates both a new lower threshold ofcompression and a new upper threshold of compression. Each new thresholdof compression may be calculated by taking into account, for example, aprevious value for that threshold of compression, the new hardnesssetting for the sole 104 (determined either at step 2412 or at step2420), and one or more constants. In one embodiment, each threshold ofcompression is used in determining, at step 2800, whether the adjustmentof the sole 104 is required.

Once step 2424 or step 2428 is complete, or if it was determined eitherat step 2408 or at step 2416 that the hardness setting for the sole 104could not be changed, the intelligent system 106 displays the new(current) hardness setting for the sole 104 at step 2432. In oneembodiment, the intelligent system 106 displays the new (current)hardness setting for the sole 104 by activating at least oneelectro-luminescent element of the indicator 506. Once the intelligentsystem 106 is sure that both the “+” and “−” buttons 502, 504 are nolonger pressed (determined at step 2434), the intelligent system 106ends, at step 2436, the display of the new (current) hardness settingby, for example, deactivating (e.g., fading) the one or more activatedelectro-luminescent elements of the indicator 506. The intelligentsystem 106 then returns to step 2316 of FIG. 28.

Returning to FIG. 28, if the intelligent system 106 determines, at step2320, that a user has not entered an input, the intelligent system 106measures the sensor signal from the sensor 122 at step 2500. Referringto FIG. 30, which depicts one embodiment of a method 2500 for measuringthe sensor signal, the intelligent system 106 may first set, at step2504, the instruction clock (e.g., slow down the instruction clock) ofthe microcontroller that implements many of the steps in the methods ofFIGS. 28-33 to, for example, 1 MHz. The microcontroller's instructionclock is set to 1 MHz to conserve battery power and does not relate tothe rate at which the signal from the sensor 122 is sampled.Alternatively, the microcontroller's instruction clock may be set to adifferent frequency to conserve battery power.

Once the microcontroller's instruction clock is set, the signal from thesensor 122 is sampled at step 2508. In one embodiment, the sensor 122 isa hall effect sensor that measures a magnetic field and that outputs ananalog voltage representative of the strength of the magnetic field.Accordingly, in one embodiment of step 2508, the analog voltage issampled, compared to a voltage reference, and converted to a digitalvalue using an A/D converter. In the embodiments described herein, asmaller digital value represents a stronger magnetic field and,therefore, a greater amount of compression in the sole 104.

An external RC timer, regulated voltage with or without a divider, orother external devices can be used in the intelligent system 106 tosupply the voltage reference. Alternatively, the voltage reference maybe provided by configuration of the microcontroller. Taking an A/Dreading off the supply voltage to the sensor enables the microcontrollerto account for any slight deviations from the desired voltage since theoutput from the sensor is often ratiometric. In one embodiment, thevoltage reference can run from 1 V to 3 V and can help to increase theresolution of the signal. In alternative embodiments, the minimum andmaximum voltages can be anywhere from 0.1 V to 10 V.

In a particular implementation of step 2508, the sensor 122, which inone embodiment has the greatest settling time, is turned on first. TheA/D converter, which in one embodiment has the second greatest settlingtime, is then turned on. Following that, the electrical devicesimplementing the voltage reference are turned on. The analog voltageoutput by the sensor 122 is then sampled, compared to the voltagereference, and converted to a digital value using an A/D converter. Thesensor 122 is then turned off to conserve energy. Following that, theelectrical devices implementing the voltage reference are turned off toalso conserve energy and, lastly, the A/D converter is turned off toconserve energy. In other embodiments, the sensor 122, the A/Dconverter, and the electrical devices implementing the voltage referencemay be turned on and/or off in other orders, and may even be turned onand/or off substantially simultaneously.

Once the signal from the sensor 122 has been sampled at step 2508, acounter “n₁”, which is initially set to zero and represents the numberof samples taken, is incremented at step 2512. The digital valuerepresentative of the strength of the magnetic field sampled at step2508 is then stored in the microcontroller's memory at step 2516.

At step 2520, the counter “n₁” is compared to a first constant todetermine whether the number of samples taken is greater than the firstconstant. If so, the microcontroller's instruction clock is reset to,for example, 4 MHz and the counter “n₁” is reset to zero at step 2524.Otherwise, steps 2504, 2508, 2512, 2516, and 2520 are repeated. Bysetting the first constant to a value greater than zero, the intelligentsystem 106 is sure to sample the sensor signal a plurality of times.Typically, the value of the first constant is between two and ten.

At step 2528, a measurement of the sensor signal is determined. In oneembodiment, the measurement of the sensor signal is determined bycalculating the average of the plurality of samples of the sensor signaltaken in repeating step 2508. In another embodiment, the measurement ofthe sensor signal is determined by, for example, averaging a subset ofthe plurality of samples of the sensor signal taken in repeating step2508. In one particular embodiment, the lowest and highest sampledvalues of the sensor signal are discarded, and the remaining sampledvalues of the sensor signal are averaged to determine the measurement ofthe sensor signal. Once the measurement of the sensor signal isdetermined at step 2528, the self diagnostic and useranalysis/interaction step 2324 may be performed, as necessary. Asillustrated in FIG. 28, the intelligent system 106 then moves on to step2600.

FIG. 31 depicts one embodiment of a method 2600 for determining whetherthe sole 104 of the article of footwear 100 has compressed. In theillustrated embodiment, the method 2600 is only performed if theparameter compression flag (“COMPFLAG”) is set to 0, indicating that theintelligent system 106 has not yet detected compression in the sole 104.By default, the parameter “COMPFLAG” is initially set to 0. At step2604, a counter “FIRSTTIME” is compared to a second constant. Thecounter “FIRSTTIME” is incremented each time step 2500 (see FIGS. 23 and25) is completed (i.e., each time a measurement of the sensor signal isdetermined). If the counter “FIRSTTIME” is less than the secondconstant, the most recently determined measurement of the sensor signal(determined at step 2528 of FIG. 30) is stored in the microcontroller'smemory at step 2608 and no other steps of the method 2600 are completed.In one embodiment, the microcontroller employs a first-in-first-out(FIFO) buffer that is capable of storing a pre-determined number ofmeasurements of the sensor signal, for example between ten and 30. Insuch an embodiment, once the FIFO buffer is full, each time a newlydetermined measurement of the sensor signal is to be stored in the FIFObuffer, the oldest determined measurement of the sensor signal stored inthe FIFO buffer is discarded.

If the counter “FIRSTTIME” is greater than the second constant, theintelligent system 106 proceeds to perform step 2612. In one embodiment,the value for the second constant is between 15 and 30. In such anembodiment, step 2500 (i.e., the step of measuring the sensor signal) isguaranteed to be repeated a plurality of times to obtain a plurality ofmeasurements of the sensor signal before the intelligent system 106proceeds to step 2612.

In one embodiment, an average of a plurality of previously obtainedmeasurements of the sensor signal (each measurement of the sensor signalbeing previously determined at step 2528 of FIG. 30 and stored in themicrocontroller's memory at step 2608) is calculated at step 2612. Themeasurement of the sensor signal most recently determined at step 2528is not, however, included in the calculation of this average. Aparameter “valdiff”, which represents the difference between the averagecalculated at step 2612 and the measurement of the sensor signal mostrecently determined at step 2528, is then determined at step 2616. Theparameter “valdiff” is then compared to a third constant at step 2620.If the parameter “valdiff” is greater than the third constant, the mostrecently obtained measurement of the sensor signal is smaller than theaverage of the plurality of previously obtained measurements of thesensor signal by at least the amount of the third constant and the sole104 has started to compress. In such a case, the intelligent system 106increments a counter “n₂” at step 2624, which is initially set to zero.Otherwise, if the parameter “valdiff” is less than the third constant,the intelligent system 106 returns to step 2608 to store the mostrecently obtained measurement of the sensor signal in themicrocontroller's memory and to reset the counter “n₂” to zero. Thevalue for the third constant may vary depending on, for example, thethickness of the midsole, the noise of the sensor signal, and/or thesampling rate (8 bit or 16 bit). For example, the value for the thirdconstant may be between 2 and 16 for an 8 bit system and between 2 and64 for a 16 bit system.

At step 2628, the counter “n₂” is compared to a fourth constant. If thecounter “n₂” is greater than the fourth constant, the intelligent system106 determines that the sole 104 has compressed and sets the parameter“COMPFLAG” equal to 1 at step 2632. The intelligent system 106 alsosets, at step 2632, the parameter “peak” equal to the most recentlydetermined measurement of the sensor signal, and increments the counter“STEP”, which is described below.

In one embodiment, the fourth constant of step 2628 is chosen so thatthe comparison of step 2620 must be true a number of consecutive timesbefore the intelligent system 106 will determine the sole 104 to havecompressed and, consequently, proceed to step 2632. In one embodiment,the fourth constant is between two and five. With the fourth constantset equal to five, for example, step 2620 would need to be true sixconsecutive times for the intelligent system 106 to determine that thesole 104 of the article of footwear 100 has compressed and,consequently, proceed to step 2632.

Upon completion of step 2608 or 2632, or where the counter “n₂” is notgreater than the fourth constant, the intelligent system 106 moves on tostep 2700.

FIG. 32 depicts one embodiment of a method 2700 for performing initialcalculations to determine whether an adjustment of the sole 104 of thearticle of footwear 100 is required. In the illustrated embodiment, themethod 2700 is only performed if the parameter “COMPFLAG” is set to 1,meaning that the intelligent system 106 has detected compression in thesole 104. In other words, the method 2700 is only performed if step 2632of method 2600 has been performed. In one embodiment, following thecompletion of step 2632, another measurement of the sensor signal isobtained (i.e., the method 2500 of FIG. 30 is again performed) beforethe method 2700 is performed.

In the embodiment illustrated in FIG. 32, the intelligent system 106first increments, on each iteration through the steps of the method2700, a timer at step 2704. If the timer is greater than a chosenmaximum value, indicating that step 2712 of the method 2700 iscontinually being repeated, the intelligent system 106 proceeds tore-set both the parameter “COMPFLAG” and the timer to zero at step 2708.Otherwise, if the timer is less than the chosen maximum value, theintelligent system proceeds to step 2712.

At step 2712, the intelligent system 106, which knows that the sole 104has recently compressed and may still be compressing, determines themaximum amount of measured compression in the sole 104. Specifically,the intelligent system 106 determines, at step 2712, the real peak valuefor the amount of compression in the sole 104. In one embodiment, theintelligent system 106 does so by determining if the sole 104 is stillcompressing. More specifically, the intelligent system 106 compares themost recently obtained measurement of the sensor signal to the value ofthe parameter “peak” determined at step 2632 of FIG. 31 (this is why inone embodiment, as stated above, following the completion of the step2632, another measurement of the sensor signal is obtained before themethod 2700 is performed). If the most recently obtained measurement ofthe sensor signal is lower than the value of the parameter “peak”(indicating greater and, therefore, continued compression in the sole104), the value of the parameter “peak” is reset to that most recentlyobtained measurement of the sensor signal and a new measurement of thesensor signal is obtained for comparison to the newly reset value of theparameter “peak”. In one embodiment, this comparison and the describedsubsequent steps continue until the most recently obtained measurementof the sensor signal is greater than the value of the parameter “peak”(indicating less compression in the sole 104). If the most recentlyobtained measurements of the sensor signal are greater than the value ofthe parameter “peak” a certain number of consecutive times (indicatingexpansion or decompression of the sole 104), the value of the parameter“peak” truly represents the maximum amount (or real peak) of measuredcompression in the sole 104. Otherwise, if the most recently obtainedmeasurements of the sensor signal are not greater than the value of theparameter “peak” a certain number of consecutive times (i.e., if arecently obtained measurement of the sensor signal is lower than thevalue of the parameter “peak”), the intelligent system 106 sets thevalue of the parameter “peak” equal to the recently obtained measurementof the sensor signal that is lower than the value of the parameter“peak” and a new measurement of the sensor signal is obtained forcomparison to the newly reset value of the parameter “peak”. Theintelligent system 106 then continues to proceed as described above.

Once the maximum amount of measured compression in the sole 104 has beendetermined, the intelligent system 106 determines, at step 2716, whetherthere is a change in a surface condition on which the article offootwear 100 is used. In one such embodiment, the intelligent system 106calculates the absolute compression in the sole 104 over time and thedeviation of the compression in the sole 104 over time or anapproximation therefor.

It should be understood that over time, the intelligent system 106 willcalculate, at step 2712, a plurality of “peak” values that eachrepresent the maximum amount of measured compression in the sole 104(e.g., the intelligent system 106 will calculate one such “peak” valueon each step of a wearer of the article of footwear 100). These “peak”values may be stored in the microcontroller's memory, for example in aFIFO buffer of an appropriate size. Accordingly, a short-term peakaverage may be calculated at step 2716 by averaging a certain number ofthose most recently calculated peak values. The average calculated atstep 2612 on the most recent iteration through the steps of the method2600 (see FIG. 31) may then be subtracted from that short-term peakaverage. In one embodiment, this difference represents the absolutecompression in the sole 104 over time.

The deviation (for example, a standard deviation or an approximationtherefor) of the peak values most recently calculated at step 2712 mayalso be calculated at step 2716 to represent the deviation of thecompression in the sole 104 over time. In one embodiment, this involvescalculating a long-term peak average by averaging, for example, agreater number of the most recently calculated “peak” values than asdescribed above for the short-term peak average. The long-term peakaverage may then be used for comparison to the instantaneous “peak”values determined at step 2712 in calculating the deviation of the peakvalues or an approximation therefor. Additionally or alternatively, aplurality of further values may be calculated at step 2716 for use inrefining or determining the state of the sole 104.

Having calculated both the absolute compression in the sole 104 overtime and the deviation of the compression in the sole 104 over time, theintelligent system 106 can compare the two to determine whether there isa change in the surface condition on which the article of footwear isbeing used. Generally, the intelligent system 106 can determine a changein the surface condition on which the article is being used by comparingtwo parameters; one parameter remaining at least substantially constant,while the other parameter changes when there is a change in the surfacecondition. In addition to the absolute compression and the deviationdescribed above, the parameters can include, for example, anacceleration profile, a compression profile, a strike pattern, andcompression force.

Typically, a decrease in the absolute compression in the sole 104 overtime together with substantially no change in the deviation of thecompression in the sole 104 over time, or an increase in the deviationof the compression in the sole 104 over time together with substantiallyno change in the absolute compression in the sole 104 over time,indicates that a wearer of the article of footwear 100 has moved from ahard ground surface (e.g., pavement or an asphalt road) to a soft groundsurface (e.g., a soft forest ground). Conversely, an increase in theabsolute compression in the sole 104 over time together withsubstantially no change in the deviation of the compression in the sole104 over time, or a decrease in the deviation of the compression in thesole 104 over time together with substantially no change in the absolutecompression in the sole 104 over time, indicates that a wearer of thearticle of footwear 100 has moved from a soft ground surface to a hardground surface. Where there is little or no change in both the absolutecompression in the sole 104 over time and the deviation of thecompression in the sole 104 over time, there is likely no change in thesurface condition on which the article of footwear 100 is used.Accordingly, by comparing the absolute compression in the sole 104 overtime to the deviation of the compression in the sole 104 over time, theintelligent system 106 may determine whether there has been a change inthe surface condition on which the article of footwear 100 is being usedand, if so, may determine what that change is. In one embodiment, tocompare the absolute compression in the sole 104 over time to thedeviation of the compression in the sole 104 over time, the intelligentsystem 106 computes a ratio of the two measurements.

In one particular embodiment, the intelligent system 106 only determineswhether there has been a change in the surface condition on which thearticle of footwear 100 is being used and, if so, what that change isafter a wearer of the article of footwear 100 has taken a plurality ofsteps, either initially or after the intelligent system 106 last madesuch determinations. For example, in one embodiment, the intelligentsystem 106 does not make such determinations until the wearer of thearticle of footwear has taken between 15 and 30 steps, either initiallyor after the intelligent system 106 last made such determinations.

At step 2716, the intelligent system 106 also resets the parameter“COMPFLAG” to 0. After determining whether there has been a change inthe surface condition on which the article of footwear 100 is used andresetting the parameter “COMPFLAG” to 0, the intelligent system 106determines whether a wearer of the article of footwear 100 has taken acertain number of steps by comparing, at step 2720, the counter “STEP”to a fifth constant. If the counter “STEP” is greater than the fifthconstant, meaning that the wearer of the article of footwear 100 hastaken a certain number of steps, the intelligent system 106 proceeds tostep 2800. If not, no adjustment to the sole 104 is made. Instead, theintelligent system 106 enters a sleep mode at step 2724 for a period oftime (e.g., between 200 and 400 milliseconds) to conserve energy beforereturning to step 2316 in FIG. 28. Typically, the value of the fifthconstant is between two and six. Moreover, the counter “STEP” may beincremented every time the parameter “COMPFLAG” is set to 1 (see step2632 in FIG. 31).

FIG. 33 depicts one embodiment of a method 2800 for performingadditional calculations to determine whether an adjustment of the sole104 of the article of footwear 100 is required and, if so, for adjustingthe sole 104. At step 2804, the same comparison as at step 2720 of FIG.32 is made. If the counter “STEP” is less than the fifth constant, theintelligent system 106 returns to step 2316 of FIG. 28. If, on the otherhand, the counter “STEP” is greater than the fifth constant, theshort-term peak average (determined at step 2716 of FIG. 32) may beadjusted, at step 2808, for comparison to the one or more thresholds ofcompression determined either at step 2424 or at step 2428 of FIG. 29.In a particular embodiment, if the surface condition on which thearticle of footwear 100 is used last changed to a hard ground surface,no adjustment to the short-term peak average is made. On the other hand,if the surface condition on which the article of footwear 100 is usedlast changed to a soft ground surface, the short-term peak average isdecreased by a certain amount, thereby causing the intelligent system106 to think that there was more compression than there actually was andencouraging the intelligent system 106 to harden the sole 104 of thearticle of footwear 100. This latter adjustment is equivalent tochanging the thresholds of compression employed at steps 2812 and 2832.

At step 2812, it is determined, by comparing the (un)adjusted value forthe short-term peak average determined at step 2808 to the lowerthreshold of compression determined either at step 2424 or at step 2428of FIG. 29, whether the compression in the sole 104 is less than thatlower threshold of compression. If so, it is determined, at step 2816,whether the parameter “softhard” equals 1, meaning that the sole 104 ofthe article of footwear was most recently hardened. If so, the counter“STALL” is set to 0 at step 2818 and compared to a sixth constant atstep 2820. If not, the counter “STALL” is not reset to 0, but is simplycompared to the sixth constant at step 2820. If the counter “STALL” isless than the sixth constant, meaning that motor 132 has not beenblocked a pre-determined number of consecutive times when theintelligent system 106 has attempted to move the motor 132 backward tosoften the sole 104, the motor 132 is moved backward, at step 2824, tosoften the sole 104. The parameter “softhard” is then set to 0 at step2828, indicating that the sole 104 of the article of footwear 100 wasmost recently softened by moving the motor 132 backward. If, on theother hand, the counter “STALL” is determined at step 2820 to be greaterthan the sixth constant, meaning that the motor 132 has been blocked apre-determined number of consecutive times when the intelligent system106 has attempted to move the motor 132 backward to soften the sole 104,the motor 132 is not moved backward. Instead, the intelligent system 106returns to perform step 2316 of FIG. 28. In one embodiment, the sixthconstant is between three and ten.

If it is determined, at step 2812, that the compression in the sole 104is greater than the lower threshold of compression determined either atstep 2424 or at step 2428 of FIG. 29, the intelligent system 106 movesto step 2832. At step 2832, it is determined, by comparing the(un)adjusted value for the short-term peak average determined at step2808 to the upper threshold of compression determined either at step2424 or at step 2428 of FIG. 29, whether the compression in the sole 104is greater than that upper threshold of compression. If so, it isdetermined, at step 2836, whether the parameter “softhard” equals 0,meaning that the sole 104 of the article of footwear was most recentlysoftened. If so, the counter “STALL” is set to 0 at step 2838 andcompared to a seventh constant at step 2840. If not, the counter “STALL”is not reset to 0, but is simply compared to the seventh constant atstep 2840. If the counter “STALL” is less than the seventh constant,meaning that the motor 132 has not been blocked a pre-determined numberof consecutive times when the intelligent system 106 has attempted tomove the motor 132 forward to harden the sole 104, the motor 132 ismoved forward, at step 2844, to harden the sole 104. The parameter“softhard” is then set to 1 at step 2848, meaning that the sole 104 ofthe article of footwear 100 was most recently hardened by moving themotor 132 forward. If, on the other hand, the counter “STALL” isdetermined at step 2840 to be greater than the seventh constant, meaningthat the motor 132 has been blocked a pre-determined number ofconsecutive times when the intelligent system 106 has attempted to movethe motor 132 forward to harden the sole 104, the motor 132 is not movedforward. Instead, the intelligent system 106 returns to perform step2316 of FIG. 28. In one embodiment, the seventh constant is betweenthree and ten.

If it is determined, at step 2832, that the compression in the sole 104is lower than the upper threshold of compression determined either atstep 2424 or at step 2428 of FIG. 29 (meaning that the compression inthe sole 104 lies between the lower and upper thresholds ofcompression), the intelligent system 106 does not move the motor 132 toadjust the sole 104, but instead returns to perform step 2316 of FIG.28.

With reference to FIG. 2B, it should be understood that, in oneembodiment, moving the motor 132 backward or forward as described aboveactually means running the motor 132 in one direction or another todrive the transmission element 134 in one direction or another (e.g.,clockwise or counter-clockwise). Consequently, the limiter 128, which isthreadedly engaged by the transmission element 134, is moved backward orforward relative to the expansion element 126, as shown generally byarrow 140 in FIG. 2B. As such, the sole 104 may be softened or hardened.

After having begun to move the motor 132 either at step 2824 or at step2844, the voltage of the battery powering the intelligent system 106 issampled a first time at step 2852. The voltage of the battery will havedropped as a result of starting the motor 132 movement. After a briefpassage of time, for example about 5 to about 40 milliseconds, thevoltage of the battery is sampled a second time at step 2856. If themotor 132 is moving freely, the voltage of the battery will haveincreased and thus the second sample of the battery voltage will begreater than the first sample of the battery voltage. If, on the otherhand, the motor 132 is blocked, the voltage of the battery will havedropped even further than it did when the motor 132 first started tomove and, thus, the second sample of the battery voltage will be lessthan the first sample of the battery voltage. At step 2860, the secondsample of the battery voltage is compared to the first sample of thebattery voltage. If the second sample of the battery voltage is lessthan the first sample of the battery voltage, the counter “STALL” isincremented and the motor 132 turned off at step 2864, as the motor 132is blocked. If, on the other hand, the second sample of the batteryvoltage is greater than the first sample of the battery voltage, themotor 132 is allowed to move for a period of time (for example, lessthan 300 milliseconds), as it is moving freely, before being turned offat step 2868.

Following step 2864 or step 2868, the intelligent system 106 returns tostep 2316 of FIG. 28 for the next iteration through the steps of themethod 2300.

FIG. 34 depicts another possible algorithm that may be performed by theintelligent system 106. In particular, FIG. 34 illustrates oneembodiment of a method 4000 for modifying a performance characteristicof an article of footwear designed for use in basketball or othersporting activity requiring similar physical movements and including anintelligent system. The method 4000 can include any of the other aspectsof the previously described algorithms.

The control algorithm is adapted to provide appropriate control of thestiffness of the article of footwear dependant upon the specificrequirements of the footwear. In the example embodiment of FIG. 34, thecontrol algorithm is adapted to provide stiffness control for abasketball shoe. This algorithm is designed to adjust the stiffness formotions including running, jumping, landing, cutting, turning, and otherphysical motions associated with basketball. Further, this algorithm isintended to provide immediate responsiveness of the intelligent system106 to adjust the appropriate performance characteristic of the shoe.

The method 4000 begins by providing power to the intelligent system. Forexample, a battery may act as the power source and may be installed inthe intelligent system at step 4010. Once the battery is installed inthe intelligent system, the intelligent system may enter a “Deep Sleep”mode at step 4020. The “Deep Sleep” mode can minimize the activity andpower requirements of the intelligent system when not in use to conservebattery power. For example, in a “Deep Sleep” mode, any LED or otherindicators may be turned off, the motor can be moved to place theadjustable element in a “soft” configuration, and the motor can then beturned off, power to all other extraneous systems and elements can beturned off, and power to the control unit can be minimized. In oneembodiment, only power to a single input mechanism need be maintained,so that the system can be turned on upon activation of that inputmechanism.

The input mechanism used to turn the intelligent system on may be a userinput interface such as a button or capacitive user interface, avibration sensor that activates the intelligent system upon sensing avibration (which will happen whenever the shoe is in use), a pressuresensor within the shoe that can activate the intelligent system uponsensing a force (indicating that the shoe is being put on), a sensorcalibrated to activate the intelligent system upon sensing a change incapacitance inside the upper (such as the change in capacitanceresulting from a foot being inserted), a heat sensor calibrated toactivate the intelligent system upon sensing a certain temperature (suchas the rise in temperature within a shoe after a foot is inserted), orother appropriate mechanism. In an alternative embodiment, more than oneof the input mechanisms can be used. For example, the footwear couldemploy both a user interface and a vibration sensor to turn theintelligent system on from a “Deep Sleep” mode 4020.

According to the method 4000, the intelligent system 106 can be turnedon by a user input 4030 from a “Deep Sleep” mode 4020 by simultaneouslypressing the “+” and “−” buttons on a user interface. Alternatively,only one of the “+” and “−” buttons need be pressed or the user inputcould be triggered through the capacitive user interface. Upon aninitial signal from the user interface, an “ON” sequence 4040 isinitiated. This sequence includes powering up any systems and sensorsrequired for the operation of the intelligent system 106, and poweringup any indicators, such as, but not limited to, LED indicators thatprovide information to a wearer. The “ON” sequence 4040 can also includedriving the motor, for example for about 200 milliseconds, to “stiffen”the adjustable element to an initial operating stiffness. In analternative embodiment, the “ON” sequence can drive the motor for agreater or lesser time, or at a higher or lower speed, to vary theinitial operating stiffness based on the specific requirements of theshoe and the wearer. In a further alternative embodiment, the adjustableelement need not be adjusted upon execution of an “ON” sequence.

Once the intelligent system 106 is on, it initiates a micro-controllerprogram 4050 to operate the intelligent system 106. This program 4050may include a number of functions. The micro-controller program 4050obtains data from any of one or more sensors adapted to provide relevantinformation to the intelligent system 106. This data can then besampled, for example at 1500 Hz, and filtered before being processed bythe micro-controller program 4050. In an alternative embodiment, datamay be sampled at any rate necessary to provide the appropriateinformation to the micro-controller program 4050. This sample rate mayrange from about 1 Hz to about 100 kHz, or more preferably from about100 Hz to about 5000 Hz. If multiple sensors are utilized, each sensormay be sampled at a different frequency, based on the function of thesensor and the requirements of the micro-controller program 4050.Alternatively, the sensors may all be sampled at the same sample rate.In one embodiment of the invention, the power to a sensor can be turnedon and off between readings, in order to save energy.

A number of different forms of filtering may be applied to the sampleddata to improve the quality of the data processed by the controlalgorithm of the micro-controller program 4050. These forms of filteringmay include, but are not limited to, high-pass, low-pass, and/orband-pass filtering. Alternatively, no filtering of the sampled dataneed be carried out prior to processing by the control algorithm. In oneembodiment, a floating memory can be employed to store data receivedfrom the sensor or sensors. One example of floating memory can storesixteen values, thereafter, upon the seventeenth value being calculated,the first one is deleted from the memory and the new one is added. Inalternative embodiments, the memory may be able to store a greater orsmaller number of data readings.

While in the “ON” mode, a user can change the preference settings of thefootwear by pressing one of the “+” or “−” buttons on the user interfaceor operating the capacitive user interface, as described hereinabove. Inone example embodiment, upon pressing the “+” button 4060, theintelligent system 106 will increase the threshold for the compression,while pressing the “−” button 4070 will result in the intelligent system106 decreasing the threshold for the compression. As a result, therequired compression that must be sensed by the intelligent system 106before a change in the stiffness of the footwear is implemented can bechanged by a user, depending upon a given user's personal preferences,weight, or running style, or upon the sport being performed. See, forexample, FIG. 29.

In one embodiment, the intelligent system 106 comprises multipleperformance characteristic settings, for example, nine different“hardness” threshold settings, or states, from a maximum hardnessthreshold to a minimum hardness threshold. In this embodiment, bypressing the “+” button 4060 (or otherwise actuating a user interface),the micro-controller program 4050 will check to see if the hardnessthreshold setting is at its maximum value. That means it checks to seeif the intelligent system 106 can further increase the hardnessthreshold of the sole of the footwear. If further increasing of thehardness threshold of the sole of the footwear is possible, themicro-controller program 4050 will instruct the intelligent system 106to change the threshold 4080 of the sole of the footwear based on theinput from the user. In one embodiment, a single press of the “+”button, or otherwise actuating a user interface, can increase thehardness threshold setting by a single degree, while in alternativeembodiments a single press of the button by a user can increase thehardness threshold by a greater degree. In alternative embodiments, theintelligent system 106 can include a greater or smaller number ofthreshold settings (e.g., hardness) from, for example, two to twentysettings.

In the same manner, by pressing the “−” button 4070 (or otherwiseactuating a user interface), the micro-controller program 4050 willcheck to see if the hardness threshold setting is at its minimum value.If a further decreasing of the hardness threshold of the sole of thefootwear is possible, the micro-controller program 4050 will instructthe intelligent system 106 to change the hardness threshold 4080 of thesole of the footwear based on the input from the user. As in the casefor increasing the hardness threshold, the value by which the hardnessthreshold is decreased can be set to any number of values based on therequirements of the user. This value by which the hardness threshold isincreased or decreased by a single press of the “+” button 4060 or the“−” button 4070 may be constant or vary depending upon the setting whenthe button is depressed.

Once a maximum or minimum threshold is reached, pressing the “+” button4060 or the “−” button 4070 to further increase or decrease the settingwill have no further effect. In one embodiment, a LED, or a series ofLEDS, can be used to display the current hardness, and/or hardnessthreshold setting on the article of footwear, or can be used to indicatewhen a change is being made to the hardness threshold setting. Thisvalue may be constantly displayed on the LEDs, or turn off after a settime to conserve power.

In an alternative embodiment, the “+” button 4060 or “−” button 4070 canbe used to directly change the stiffness of the sole of the footwear, orchange another parameter associated with the intelligent system 106. Ina further alternative embodiment, these functions may be performed whenthe intelligent system 106 is in any operational mode, including forexample an “OFF”, “DEEP SLEEP”, or “Semi-Sleep” mode.

In one aspect of the micro-controller program 4050, the intelligentsystem 106 can count the number of steps n_(s) taken by a wearer. Thiscan be achieved, for example, by any of the methods describedpreviously. An adjustment of the compression of the intelligent system106 can then be carried out after a set number of steps n_(s), forexample every eight steps. In alternative embodiments, an adjustment canbe carried out after fewer or greater steps, depending upon therequirements of the user and the specific task being performed. In thisembodiment, the micro-controller records the sensor readings for eightconsecutive steps 4140. Upon the eighth step, the sensor readings can beprocessed to calculate whether an adjustment 4150 to the compression ofthe intelligent system 106 is required. This can be achieved, forexample, by averaging the value for the eight steps and calculatingwhether this value is greater than the compression threshold required toinitiate a change in the compression of the intelligent system 106. Inan alternative embodiment, a number of different algorithms can beemployed to calculate whether the compression of the intelligent system106 should be adjusted. These algorithms can include calculations of therange of compressions throughout the previous eight steps, calculationsof higher order responses of the system, filtering of the results tocompensate for any spurious results, or other appropriate algorithms.

Once the micro-controller program 4050 has determined whether anadjustment of the compression 4150 is required, the sequence is repeatedand compression measurements are taken for another n_(s) steps. Inalternative embodiments of the invention, readings can be taken for aset number of samples, rather than for a set number of user steps beforethe micro-controller program 4050 determines if an adjustment of thecompression is required. The adjustment is made to either stiffen orsoften the sole of the shoe, typically while the wearer's foot is in theair.

An adjustment to a performance characteristic of shoe including theintelligent system 106 can also be made immediately upon the sensing ofan extreme condition, for example over-compression, 4160, such as may beproduced by a jump, a landing, a cut, or other movement associated withbasketball, or other sports for which the footwear is configured. Anover compression 4160, produced by one of the above-mentionedactivities, can result in an irregular profile being observed by asensor. Excessive over-compression can be defined internally by a seriesof calculations involving the percentage over-compression in relation tothe current threshold setting. If there is a compression which “bottomsout” the shoe or is out of the acceptable functional range, then animmediate motor movement adjusting (e.g., stiffening) the shoe 4170 canbe initiated. In addition, the threshold setting can be temporarilychanged to accommodate the new motor setting. This adjustment 4170 canbe initiated, for example, after a single sensor reading exceeds the setover-compression, after the average of a number of samples exceeds thelimit for acceptable overcompression, or after a set number of samplesall exceed the required amount. In order for the intelligent system 106to respond quickly enough to effectively support the movement of theuser, the number of samples over which an over-compression should bemeasured must be small enough, and the sample rate of the sensor andmicro-controller program 4050 must be high enough, to sense an activemovement of the user before the movement has been completed.

In one embodiment, upon a compression being sensed, a floating memorybuffer can store a number of measurements and compare these measurementsto determine whether a peak condition has been reached. For example, ifthe values continue to increase over the buffered measurements, a peakcondition has yet to be reached, while if the values begin to decreaseover the buffered measurements then a peak condition may have alreadyoccurred. This buffer may continuously update to provide continuousinformation on whether a peak condition is about to occur, is occurring,or has passed; the intelligent system responding accordingly. The numberof values stored in this floating memory can be preprogrammed into theintelligent system or be adjustably set by a user. In a furtherembodiment, information associated with previously sensed peakconditions, such as the magnitude of the over-compression and the timebetween over-compressions, can be stored within the intelligent system106. This information can be used as a predictive tool to predict thelikelihood of an over-compression occurring at a future time based on arepeated pattern of over-compressions being sensed. Prior informationrelated to sensed peak conditions can also be used to determine whethera specific athletic activity is being performed, or a specific wearer iswearing the footwear, and then adjust a performance characteristic ofthe footwear accordingly.

As previously shown in FIG. 6, the system 106 can include an interfaceport 160 to allow information to be downloaded from the system 106 to anexternal processor. In one embodiment, peak condition information can bedownloaded to an external processor for analysis; allowing an athletes'performance to be analyzed in order to aid training. In a furtherembodiment, different algorithms can be uploaded from an external sourceinto the intelligent system 106, for example to provide specificperformance algorithms for different users of an article of footwear ordifferent athletic activities being carried out by a wearer.

Once an immediate adjustment 4170 has been carried out, the algorithmreturns to the main micro-controller program 4050 and continues tosample data as before. In one embodiment, once the active movementproducing the over-compression has been completed, the stiffness of theintelligent system 106 is returned to its value before theover-compression was measured. In an alternative embodiment, the changeto the stiffness can remain until the next set number of steps have beenmeasured and processed, after which an adjustment to the stiffness canbe made, if so required. Due to the nature of basketball, where a widevariety of movements may be performed by a user over a short period oftime, the system can be configured to ignore slight compressions relatedto bobbing or standing by setting the compression threshold high enoughthat only the running, cutting, jumping, landing, and other extrememovements result in the stiffness being adjusted immediately. Asdescribed above, the actual threshold value can be adjusted by a userthrough the user interface to fit a specific user and/or performancerequirements.

In the event that no activity is sensed by one or more of the sensorsfor a certain period of time, the intelligent system 106 may enter a“Semi-Sleep” mode 4110. For example, if no activity is sensed 4100, forexample for 5 minutes, the “Semi-Sleep” mode 4110 may be initiated. Inalternative embodiments, a greater or lesser time period can be requiredbefore the “Semi-Sleep” mode 4110 is initiated. The required time periodmay be imbedded in the micro-controller program 4050 or set by a user.The “Semi-Sleep” mode 4110 can be indicated by a flash from a LED onregular intervals, such as, for example, every five seconds. Inalternative embodiments, the LED can flash at a shorter or longerinterval, flash in a different pattern, or remain on in order toindicate that the system 106 is in the “Semi-Sleep” mode 4110. It shouldbe noted that in an article of footwear including a LED, or a series ofLEDs, any variety of flashes and or sequences of flashes can be used toindicate any of one or more functions of the intelligent system 106.

In the “Semi-Sleep” mode 4110, the intelligent system 106 can beconfigured to power up for a brief period at regular intervals to checkfor activity from one or more sensors. This interval can, in oneembodiment, be every fifteen seconds, although shorter or longerintervals between checks may be employed in alternative embodiments. Ifactivity is sensed, the intelligent system 106 can return to themicro-controller program 4050. If no activity is sensed for an extendedtime period 4120, for example two hours, the intelligent system 106 canbe returned the “DEEP SLEEP” mode 4020 or an “OFF” mode 4130. Inalternative embodiments, the extended period of no activity 4120required for the footwear to be idle before the “DEEP SLEEP” 4020 or the“OFF” mode 4130 is enabled may be greater than or less than two hoursand can range from, for example, ten minutes to 10 hours.

The intelligent system 106 can be manually put into the OFF mode 4130 or“Deep Sleep” mode 4020 by pressing both the “+” and “−” buttons on theuser interface simultaneously 4090. Alternatively, the capacitive userinterface could be used to send the necessary signal to the intelligentsystem 106. To avoid inadvertently turning off the intelligent system106, the micro-controller program 4050 can, in one embodiment, requirethat the “+” and the “−” buttons 4090 be held down for a certain periodof time before an instruction to initiate the OFF mode 4130 or the “DeepSleep” mode 4020 is performed. In one embodiment, both the “+” and “−”buttons 4090 may need to be pressed for at least one second before theOFF mode 4130 or the “Deep Sleep” mode 4020 is initiated. In alternativeembodiments, a greater or lesser time period may be required for boththe “+” and “−” buttons 4090 to be pressed in order to initiate the OFFmode 4130 or the “Deep Sleep” mode 4020. In another embodiment, noextended time period may be required at all, but instead the OFF mode4130 or the “Deep Sleep” mode 4020 may be initiated immediately uponboth the “+” and “−” buttons 4090 being pressed simultaneously. In thisembodiment, initiating the OFF mode 4130 or the “Deep Sleep” mode 4020includes a light “OFF” sequence accompanied by a movement of the motorto the soft configuration.

FIG. 35 illustrates one embodiment of an electrical circuit 2900suitable for implementing an intelligent system 106 in a left shoe inaccordance with the invention. FIG. 36 illustrates one embodiment ofanother electrical circuit 2900′ suitable for implementing theintelligent system 106 in a right shoe in accordance with the invention.As illustrated, the electrical circuits 2900, 2900′ are similar in allrespects except that each circuit 2900, 2900′ includes a differentnumber of, and a different placement of, 0Ω jumper resistors 2904,2904′. For each circuit, the presence of a 0Ω jumper resistor 2904,2904′ is necessary when one physical wire is to cross over another. Inaddition, the number and placement of the 0Ω jumper resistors 2904,2904′ differ in each circuit 2900, 2900′, because the physical layoutand orientation of the circuits 2900, 2900′ differ in the left andrights shoes. Other than the different number and placement of the 0Ωjumper resistors 2904, 2904′ in the left and right shoes, however, theelectrical connections in the two circuits 2900, 2900′ are the same.Accordingly, only the electrical circuit 2900 that is suitable forimplementing the intelligent system 106 in a wearer's left shoe isdiscussed below.

With reference to FIG. 35, the electrical circuit 2900 includes a powersource 2906, a voltage regulator system 2908, a sensing system 2912, acontrol system 2916, and an actuation system 2920. In the embodimentillustrated, the power source 2906 is a 3.0 V battery and the voltageregulator system 2908 is a step-up DC-DC voltage regulator system thatemploys the MAX1724 step-up DC/DC converter manufactured by MaximIntegrated Products of Sunnyvale, Calif. The 3.0 V input voltage of thepower source 2906 is stepped-up to a higher 5.0 V output voltage at theoutput 2924 of the MAX1724 step-up DC/DC converter. It should beunderstood, however, that other types of power sources and voltageregulator systems may be used in the electrical circuit 2900.

The sensing system 2912 includes a sensor 2928 (e.g., a linearratiometric hall effect sensor) and a switch 2932. The control system2916 includes a microcontroller 2936 (e.g., the PIC16F88 microcontrollermanufactured by Microchip Technology, Inc. of Chandler, Ariz.), fiveelectro-luminescent elements 2940 (e.g., light emitting diodes), and twoswitches 2944, 2948.

The 5.0 V output 2924 of the voltage regulator system 2908 is connectedto pins 15 and 16 of the microcontroller 2936 in order to power themicrocontroller 2936. Pins 5 and 6 of the microcontroller 2936 areconnected to ground to provide the microcontroller 2936 with a groundreference. A reference voltage of approximately 1.0 V is provided to pin1 of the microcontroller 2936; however, this reference voltage may bevaried by choosing appropriate values for resistors 2952 and 2956, whichtogether form a voltage divider. Similarly, a reference voltage ofapproximately 3.0 V is provided to pin 2 of the microcontroller 2936,but this reference voltage may be varied by choosing appropriate valuesfor resistors 2960 and 2964, which together form a voltage divider.

The sensor 2928 measures the strength of the magnetic field present inthe sole 104 of the article of footwear 100 and outputs at terminal 2968an analog voltage representative of the strength of the magnetic field.Typically, the analog voltage output by the sensor 2928 is between about1.0 V and about 2.5 V. In one embodiment, the sensor 2928 outputssmaller voltages for stronger magnetic fields and, accordingly, forgreater amounts of compression in the sole 104. The analog voltageoutput by the sensor 2928 is received at pin 3 of the microcontroller2936, is compared by the microcontroller 2936 to the reference voltagespresent at its pins 1 and 2, and is converted by the microcontroller toa digital value using an A/D converter. This digital value, which in oneembodiment is smaller for stronger magnetic fields and, accordingly, forgreater amounts of compression in the sole 104, is then used by themicrocontroller 2936 to implement the method 2300 described above.

In one embodiment, the sensor 2928 is turned on to measure magneticfield strength, as described above, and then off to conserve power.Specifically, to turn on the sensor 2928, the microcontroller 2936 firstoutputs a low voltage from its pin 7. This in turn causes the switch2932 to close, thereby connecting the 5.0 V output 2924 of the voltageregulator system 2908 to the sensor 2928 and powering the sensor 2928.To turn off the sensor 2928, the microcontroller 2936 outputs a highvoltage from its pin 7. This in turn causes the switch 2932 to open,thereby disconnecting the 5.0 V output 2924 of the voltage regulatorsystem 2908 from the sensor 2928 and turning off the sensor 2928. In oneembodiment, the switch 2932 is a p-Channel MOSFET.

Similarly, to conserve power, the microcontroller 2936 may turn off thevoltage reference implemented at its pins 1 and 2. To do so, themicrocontroller 2936 outputs approximately 5.0 V at pin 9 thereof. Toturn the voltage reference implemented at its pins 1 and 2 back on, themicrocontroller outputs approximately 0 V at its pin 9.

The five electro-luminescent elements 2940 provide a visual output tothe user. For example, the five electro-luminescent elements 2940 may beused to display the current hardness/softness setting of the sole 104.As illustrated in FIG. 35, pins 17, 18, and 19 of the microcontroller2936 are connected, through resistors 2972, to the fiveelectro-luminescent elements 2940. Based on the results obtained fromimplementing the method 2300 described above, the microcontroller 2936controls the output/input at its pins 17, 18, and 19 to turn on or offone or several of the electro-luminescent elements 2940. The table inFIG. 37 illustrates the states of the input/output at pins 17, 18, and19 of the microcontroller 2936 that are required to turn on severalcombinations of the electro-luminescent elements 2940. State “0”represents a low voltage output by the microcontroller 2936 at aparticular pin; state “1” represents a high voltage output by themicrocontroller 2936 at a particular pin; and state “Z” represents ahigh input impedance created by the microcontroller at a particular pin.

Switches 2944 and 2948 are connected between ground and pins 14 and 13,respectively, of the microcontroller 2936. As described above withrespect to the method 2300, the user may close switch 2944 to connectpin 14 of the microcontroller 2936 to ground, while leaving the switch2948 open, and thereby indicate his desire to change the hardnesssetting for the sole 104 to a harder setting. Similarly, the user mayclose switch 2948 to connect pin 13 of the microcontroller 2936 toground, while leaving the switch 2944 open, and thereby indicate hisdesire to change the hardness setting for the sole 104 to a softersetting. If the user closes both switches 2944 and 2948 at the sametime, the microcontroller 2936 calls the “OFF” sequence described abovewith respect to method 2300. The user may close either switch 2944 or2948 by actuating push buttons, which are located on the outside of thearticle of footwear 100.

The actuation system 2920 includes transistor bridges 2976 and 2980, anda motor (not shown) connected in parallel with a capacitor 2984. In theembodiment illustrated in FIG. 35, the transistor bridge 2976 includesan n-Channel MOSFET (including gate G1, source S1, and drain D1) and ap-Channel MOSFET (including gate G2, source S2, and drain D2). Thetransistor bridge 2980 also includes an n-Channel MOSFET (including gateG1, source S1, and drain D1) and a p-Channel MOSFET (including gate G2,source S2, and drain D2). The source S1 of transistor bridge 2976 andthe source S1 of transistor bridge 2980 are connected to ground. Thesource S2 of transistor bridge 2976 and the source S2 of transistorbridge 2980 are connected to the positive terminal of the power source2906. The gate G1 of transistor bridge 2976 and the gate G2 oftransistor bridge 2980 are connected to pin 12 of the microcontroller2936. The gate G2 of transistor bridge 2976 and the gate G1 oftransistor bridge 2980 are connected to pin 10 of the microcontroller2936. The drain D1 of transistor bridge 2976 and the drain D2 oftransistor bridge 2980 are connected to the motor drive return terminal2988 of the motor. The drain D2 of the transistor bridge 2976 and thedrain D1 of the transistor bridge 2980 are connected to the motor driveforward terminal 2992 of the motor.

As illustrated in the table of FIG. 38, in order to drive the motorforward, the microcontroller 2936 outputs a high voltage at its pin 12and a low voltage at its pin 10. This turns on the MOSFETs of transistorbridge 2976 and turns off the MOSFETs of transistor bridge 2980. As aresult, the motor drive forward terminal 2992 is connected to thepositive terminal of the power source 2906 and the motor drive returnterminal 2988 is connected to ground, driving the motor forward. Inorder to drive the motor backward, the microcontroller 2936 outputs alow voltage at its pin 12 and a high voltage at its pin 10. This turnsoff the MOSFETs of transistor bridge 2976 and turns on the MOSFETs oftransistor bridge 2980. As a result, the motor drive forward terminal2992 is connected to ground and the motor drive return terminal 2988 isconnected to the positive terminal of the power source 2906, driving themotor backward. If the microcontroller 2936 outputs a high voltage atboth its pin 10 and its pin 12, or a low voltage at both its pin 10 andits pin 12, the motor is stopped and remains idle.

The positive terminal of the power source 2906 is also connected to pin20 of the microcontroller 2936. As such, the microcontroller 2936 cansense the voltage at the positive terminal of the power source (e.g.,can sense a battery voltage) and can use the sensed voltage inperforming the steps of the method 2300 described above. For example, asdescribed above, the microcontroller 2936 can determine from the sensedvoltage whether the motor is blocked and, if so, can stall the motor.

Pin 4 of the microcontroller 2936 is the active low reset pin of themicrocontroller 2936. It allows the microcontroller 2936 to be resetduring testing/debugging, but is not used when a wearer iswalking/running in the article of footwear 100. Similarly, pins 8 and 11of the microcontroller 2936 are used during testing/debugging, but arenot used when the wearer is walking/running in the article of footwear100. Specifically, pin 8 of the microcontroller 2936 is a data pin,which allows for the transfer of data, and pin 11 of the microcontroller2936 is a clock pin.

In addition, the electrical circuit 2900 includes a plurality of testpoints 2996 (i.e., test points TP1 through TP10) that are used duringtesting/debugging and when the power source 2906 is disconnected fromthe circuit 2900, but that are not used when the wearer iswalking/running in the article of footwear 100. For example, test pointTP1 provides the microcontroller 2936 with a reference voltage ofapproximately 1.0 V; test point TP2 provides the microcontroller 2936with a reference voltage of approximately 3.0 V; test point TP3 providesa simulated reading from the sensor 2928 to the microcontroller 2936;test point TP4 provides power to the microcontroller 2936; and testpoint TP5 provides the electrical circuit 2900 with a reference ground.Test point TP6 connects to the clock pin 11 of the microcontroller 2936and test point TP9 allows the microcontroller 2936 to be reset. Testpoints TP7, TP8, and TP10 allow data to be transferred to and from themicrocontroller 2936 during testing/debugging. In one embodiment, forexample, test points TP7 and TP8 may simulate the opening and closing ofthe switches 2948 and 2944, respectively, during testing/debugging.

FIGS. 39A and 39B depict an article of footwear 1500 including analternative intelligent system 1506. The article of footwear 1500includes an upper 1502, a sole 1504, and the intelligent system 1506.The intelligent system 1506 is disposed in the rearfoot portion 1508 ofthe sole 1504. The intelligent system 1506 includes a driver 1531 and anadjustable element 1524 of one or more similar components. Theadjustable element 1524 is shown in greater detail in FIG. 39B andincludes two dual density tuning rods 1525 that are rotated in responseto a corrective driver signal to modify a performance characteristic ofthe footwear 1500. The dual density rods 1525 have an anisotropicproperty and are described in detail in U.S. Pat. No. 6,807,753, theentire disclosure of which is hereby incorporated herein by reference.The dual density rods 1525 are rotated by the motor 1532 and thetransmission element 1534 to make the sole 1504 harder or softer. Thetransmission element 1534 is coupled to the dual density rods 1525 atabout a lateral midpoint of the rods 1525, for example by a rack andpinion or worm and wheel arrangement.

FIG. 40A depicts an article of footwear 1600 including an alternativeintelligent system 1606. FIGS. 40B-40D depict the adjustable element1624 in various states of operation. The article of footwear 1600includes an upper 1602, a sole 1604, and the intelligent system 1606.The intelligent system 1606 includes a driver 1631 and an adjustableelement 1624. The adjustable element 1624 includes two multi-densityplates 1625, 1627. One of the plates, in this embodiment lower plate1627, is slid relative to the other plate, in this embodiment upperplate 1625, by the driver 1631, in response to the corrective driversignal to modify the performance characteristic of the shoe (arrow1680).

The plates 1625, 1627 are made of alternating density materials. Inparticular, the plates 1625, 1627 are made up of alternating strips of arelatively soft material 1671 and a relatively hard material 1673. Thealignment of the different density portions of the plates 1625, 1627determines the performance characteristic of the shoe. In FIG. 40B, therelatively hard materials 1673 are substantially aligned, therebyresulting in a relatively hard adjustable element 1624. In FIG. 40C, thedifferent density materials 1671, 1673 are only partially aligned,thereby resulting in a softer adjustable element 1624. In FIG. 40D, therelatively hard materials 1673 and the relative soft materials 1671 aresubstantially aligned, thereby resulting in the softest possibleadjustable element 1624.

FIGS. 41A and 41B depict an article of footwear 1700 including analternative intelligent system 1706. The article of footwear 1700includes an upper 1702, a sole 1704, and the intelligent system 1706.The intelligent system 1706 is disposed in the rearfoot portion 1708 ofthe sole 1704. The intelligent system 1706 includes a driver 1731 (notshown, but similar to those described hereinabove) and an adjustableelement 1724. The adjustable element 1724 is a multi-density heelportion 1726 that swivels relative to the sole 1704 (see arrow 1750 inFIG. 41B). Swiveling the heel portion 1726 modifies the mechanicalproperties of the footwear 1700 at a heel strike zone 1782. The heelportion 1726 swivels about a pivot point 1784 in response to a forcefrom the driver 1731.

The various components of the adjustable elements described herein canbe manufactured by, for example, injection molding or extrusion andoptionally a combination of subsequent machining operations. Extrusionprocesses may be used to provide a uniform shape, such as a singlemonolithic frame. Insert molding can then be used to provide the desiredgeometry of the open spaces, or the open spaces could be created in thedesired locations by a subsequent machining operation. Othermanufacturing techniques include melting or bonding additional elements.For example, the cylinders 448 may be joined with a liquid epoxy or ahot melt adhesive, such as EVA. In addition to adhesive bonding,components can be solvent bonded, which entails using a solvent tofacilitate fusing of various components or fused together during afoaming process.

The various components can be manufactured from any suitable polymericmaterial or combination of polymeric materials, either with or withoutreinforcement. Suitable materials include: polyurethanes, such as athermoplastic polyurethane (TPU); EVA; thermoplastic polyether blockamides, such as the Pebax® brand sold by Elf Atochem; thermoplasticpolyester elastomers, such as the Hytrel® brand sold by DuPont;thermoplastic elastomers, such as the Santoprene® brand sold by AdvancedElastomer Systems, L.P.; thermoplastic olefin; nylons, such as nylon 12,which may include 10 to 30 percent or more glass fiber reinforcement;silicones; polyethylenes; acetal; and equivalent materials.Reinforcement, if used, may be by inclusion of glass or carbon graphitefibers or para-aramid fibers, such as the Kevlar® brand sold by DuPont,or other similar method. Also, the polymeric materials may be used incombination with other materials, for example natural or syntheticrubber. Other suitable materials will be apparent to those skilled inthe art.

In a particular embodiment, the expansion element 126 can be made of oneor more various density foams, non-foamed polymer materials, and/orskeletal elements. For example, the cylinder could be made of Hytrel®4069 or 5050 with a 45 Asker C foamed EVA core. In another embodiment,the cylinder is made of Hytrel® 5556 without an inner core foam. Theexpansion element 126 can have a hardness in the range of about 40 toabout 70 Asker C, preferably between about 45 and about 65 Asker C, andmore preferably about 55 Asker C. In an alternative embodiment, thetuning rods 1525, the multiple density plates 1625, 1627, or the upperand lower support plates 114, 116 may be coated with an anti-frictioncoating, such as a paint including Teflon® material sold by DuPont or asimilar substance. The various components can be color coded to indicateto a wearer the specific performance characteristics of the system andclear windows can be provided along the edge of the sole. The size andshape of the various components can vary to suit a particularapplication. In one embodiment, the expansion element 126 can be about10 mm to about 40 mm in diameter, preferably about 20 mm to about 30 mm,and more preferably about 25 mm. The length of the expansion element 126can be about 50 mm to about 100 mm, preferably about 75 mm to about 90mm, and more preferably 85 mm.

In addition, the expansion element 126 can be integrally formed by aprocess called reverse injection, in which the cylinder 142 itself formsthe mold for the foam core 144. Such a process can be more economicalthan conventional manufacturing methods, because a separate core mold isnot required. The expansion element 126 can also be formed in a singlestep called dual injection, where two or more materials of differingdensities are injected simultaneously to create integrally the cylinder142 and the core 144.

FIG. 42 is a graph depicting a performance characteristic of anadjustable element at two different settings (curves A and B). The graphdepicts the amount of deformation of the adjustable element in a loadedcondition, i.e., under compression. As can be seen, each curve A, B hastwo distinct slopes 1802, 1804, 1806, 1808. The first slope 1802, 1806of each curve generally represents the adjustable element from firstcontact until the adjustable element contacts the limiter. During thisphase, the resistance to compression comes from the combined effect ofthe structural wall and core of the adjustable element, which compresswhen loaded. The second slope 1804, 1808 of each curve represents theadjustable element under compression while in contact with the limiter.During this phase, very little additional deformation of the adjustableelement is possible and the additional force attempts to bend or bucklethe structural wall.

At setting A, which is a relatively hard setting, the adjustable elementdeforms about 6.5 mm when a force of 800 N is applied to the adjustableelement, as represented by slope 1802. At this point, the adjustableelement has contacted the limiter and very little additional deformationis possible. As slope 1804 represents, the additional deformation of theadjustable element is only about 2 mm after an additional force of 800 Nis applied to the adjustable element. At setting B, which is arelatively soft setting, the adjustable element deforms about 8.5 mmwhen a force of 800 N is applied to the adjustable element, asrepresented by slope 1806. At this point, the adjustable element hascontacted the limiter and very little additional deformation ispossible. As slope 1808 represents, the additional deformation of theadjustable element is only about 2.5 mm after an additional force of 800N is applied to the adjustable element.

FIG. 43 depicts a flow chart representing a method of modifying aperformance characteristic of an article of footwear during use. Themethod includes monitoring the performance characteristic of the articleof footwear (step 1910), generating a corrective driver signal based onthe monitored performance characteristic (step 1920), and adjusting anadjustable element based on the driver signal to modify the performancecharacteristic of the article of footwear (step 1930). In a particularembodiment, the steps are repeated until a threshold value of theperformance characteristic is obtained (step 1940).

One possible embodiment of the monitoring step 1910 is expanded in FIG.44A. As shown, monitoring the performance characteristic involvesmeasuring a magnetic field of a magnet with a proximity-type sensor(substep 2010) and comparing the magnetic field measurement to athreshold value (substep 2020). Optionally, monitoring the performancecharacteristic may include taking multiple measurements of the magneticfield and taking an average of some number of measurements. The systemthen compares the average magnetic field measurement to the thresholdvalue (optional substep 2030). The system could repeat these steps asnecessary (optional substep 2040) until the magnetic field measurementis substantially equal to the threshold value, or within a predeterminedvalue range.

One possible embodiment of the generating step 1920 is expanded in FIG.44B. As shown, generating the corrective driver signal involvescomparing the monitored performance characteristic to a desiredperformance characteristic (substep 2050), generating a deviation(substep 2060), and outputting a corrective driver signal magnitudebased on the deviation (substep 2070). In one embodiment, the correctivedriver signal has a predetermined magnitude, such that a predeterminedamount of correction is made to the performance characteristic. In thisway, the system makes incremental changes to the performancecharacteristic that are relatively imperceptible to the wearer, therebyeliminating the need for the wearer to adapt to the changing performancecharacteristic.

FIG. 45 depicts a flow chart representing a method of providing comfortin an article of footwear. The method includes providing an adjustablearticle of footwear (step 2110) and determining a jerk value (step2120). Jerk is represented as a change of acceleration over a change intime (Δa/Δt). The jerk value can be derived from the distancemeasurement, based on the changing magnetic field, over a known timeperiod. A control system records the change in the magnetic field overtime and is able to process these measurements to arrive at the jerkvalue. The method may further include modifying a performancecharacteristic of the adjustable article of footwear based on the jerkvalue (optional step 2130), for example, to keep the jerk value below apredetermined maximum value.

Having described certain embodiments of the invention, it will beapparent to those of ordinary skill in the art that other embodimentsincorporating the concepts disclosed herein may be used withoutdeparting from the spirit and scope of the invention. Accordingly, thedescribed embodiments are to be considered in all respects as onlyillustrative and not restrictive.

1-16. (canceled)
 17. An intelligent system for adjusting a performancecharacteristic of an article of footwear, the system comprising; acontrol system; a power source electrically coupled to the controlsystem; an adjustable element; a driver coupled to the adjustableelement for adjusting the adjustable element in response to a signalfrom the control system; and at least one user interface. 18-25.(canceled)